Agriculture, Volume 12, Issue 4 (April 2022) – 131 articles

For finding more sustainable cropping systems, this study on how the farming system influences the yield and quality of potato tubers was carried out with long-term crop rotation experiment. The long-term five-field crop rotation field trial was established with the following farming system treatments: organic farming system treatments: Org I (organic control), Org II (organic crop rotation with winter cover crops) and Org III (organic crop rotation with winter cover crops and the addition of composted cattle manure); conventional farming system treatments: N0 (conventional system without fertilizers), N50 (conventional system with fertilization, N50P25K95), N100 (conventional system, N100P25K95) and N150 (conventional system, N150P25K95). The average yield (based on 3 trial years) of conventional systems was 25% higher, compared to organic systems. However, in organic systems, the yield was the most stable. The most fluctuating cropping system was the most intensively managed N150. In each trial year, the yield differed statistically and it varied from 4.7 t ha⁻¹ up to 10.9 t ha⁻¹. Org I had the same dry matter yield as the N0 system, where chemicals were used, meaning that using chemicals for plant protection but no fertilizer for growth improvement had no positive effect. In each year, the yield in Org III system was similar to N50 system. Regarding the tubers per plant, there were no differences between farming systems but there was a significant difference between the trial years. The tubers in conventional systems had a lower starch content than the organic systems. It is possible to conclude that if cover crops and manure are used, organic farming practices provide just as good results as the conventional farming with low nitrogen level. Full article

Despite the fact that consumer behaviour in the organic foods market has been the subject of numerous studies in various countries around the world, little research has been devoted to the assessment of the importance of the altruistic behaviour of consumers who prefer a local origin of such food. Therefore, the aim of this paper was to determine the motives of organic food consumers for their interest in the local origin of food in the context of behaviour defined as either altruistic or egoistic. The study was carried out among 850 consumers of organic foods in Poland. The Kruskal–Wallis test and Dunn’s post hoc test were used for the analysis of empirical data. This study shows that the emphasis on the importance of the local origin of this kind of food by organic food consumers is related to their awareness of the needs of other people; specifically, this is demonstrated by these consumers taking into account the importance of caring for the natural environment in their purchasing decisions. Therefore, this is an example of altruistic behaviour which also fits into the concept of reflexive localism. It was further determined that this consumer group has a stronger and more robust relationship with the organic food market than the market’s other members. Full article

The volatility of meat prices affects the accessibility and even food security of some consumers in Turkey. This study analyses the prices of selected livestock and a major feed component, wheat, as well as the exchange rate of the domestic currency in Turkey because imports augmented the domestic live calf and sheep supply. The analysis applies 470 price observations from January 2005 to October 2019 for each of the following price series: live calf, live sheep, feed wheat, and exchange rate of Turkish lira to US dollar. The series are analyzed by using the VAR-Asymmetric BEKK-GARCH technique. The results show that the elicited conditional variances of the return series were significantly affected by both short-term shocks and shocks across the return series. The uncertainties in the live calf, live sheep, and feed wheat markets were affected by both long-term volatilities and long-term swings in their own and the other markets, but their own market-induced effects were stronger. Similarly, the conditional variances of the returns of live calves, live sheep, and feed wheat were significantly affected by the rapid price ascent in the exchange rate and the periods of livestock imports as compared to the periods when imports were absent. The unfavorable news exerted particularly negative effects on persistent volatility in markets. Additionally, the live sheep market faced greater risks than the live calf or wheat markets and was greatly affected by the limited domestic sheep supply. Results provide knowledge useful in augmenting policy, assuring sustained accessibility to animal protein in Turkey and eliminating food insecurity. Full article

Dry direct-seeded rice sown by multifunctional seeders (MS-DDSR) has received increased attention for its high efficiency. Wheat straw returning is widely used as an important agricultural practice because it is the simplest and quickest approach to dispose of wheat straw and also improve soil quality. The study determined whether MS-DDSR after wheat straw returning could obtain a high yield and whether early nitrogen (N) application could compensate for the negative effects caused by returned wheat straw. Field experiments were performed in a split-plot design. Main plots were comprised without wheat straw returning (S0) and wheat straw returning (S1). Split plots consisted of three plots with early N application treatment: 65 (N1), 95 (N2), and 125 (N3) kg N ha⁻¹ at 0 and 20 days after sowing. S1 reduced yield, N uptake, and biomass accumulation in MS-DDSR compared to S0 because S1 negatively affected the seedling roots growth, seedling establishment, and tillering capacity of MS-DDSR. The positive interaction between wheat straw returning and early N on yield, biomass accumulation, and N uptake was likely related to the positive interaction on spikelet number per panicle, total spikelet number, and biomass accumulation after the stem elongation stage. These findings demonstrate that wheat straw returning led to poor seedling establishment and yield loss for MS-DDSR, but these negative effects could be compensated for by an appropriate increase in early N application, based on the locally recommended N application protocols. Full article

The present study aimed at investigating scientific irrigation scheduling (SIS) for the sustainable production of olive groves. The SIS allows farmers to schedule water rotation in their fields to abate crop water stress and maximize yields, which could be achieved through the precise monitoring of soil moisture. For this purpose, the study used three kinds of soil moisture sensors, including tensiometer sensors, irrometer sensors, and gypsum blocks for precise measurement of the soil moisture. These soil moisture sensors were calibrated by performing experiments in the field and laboratory at Barani Agricultural Research Institute, Chakwal in 2018 and 2019. The calibration curves were obtained by performing gravimetric analysis at 0.3 and 0.6 m depths, thereby equations were developed using regression analysis. The coefficient of determination (R²) at 0.3 and 0.6 m depth for tensiometer, irrometer, and gypsum blocks was found to be equal to 0.98, 0.98; 0.75, 0.89; and 0.82, and 0.95, respectively. After that, a drip irrigation system was installed with the calibrated soil moisture sensors at 0.3 and 0.6 m depth to schedule irrigation for production of olive groves as compared to conventional farmer practice, thereby soil moisture profiles of these sensors were obtained to investigate the SIS. The results showed that the irrometer sensor performed as expected and contributed to the irrigation water savings between 17% and 25% in 2018 and 2019, respectively, by reducing the number of irrigations as compared toother soil moisture sensors and farmer practices. Additionally, olive yield efficiencies of 8% and 9%were observed by the tensiometer in 2018 and 2019, respectively. The outcome of the study suggests that an effective method in providing sustainable production of olive groves and enhancing yield efficiency. Full article

Results from a four-year field experiment were used to evaluate the effect of conventional tillage (CT) and no-tillage (NT) systems on the yield, selected yield and crop structure elements, weed infestation, and contents of fat and glucosinolates in the seeds of winter oilseed rape (Brassica napus L. ssp. oleifera Metzg). The study proved the beneficial effect of the NT system on the winter rape seed yield only during the precipitation shortage in the growing season. In the years with a sufficient sum of precipitation, a higher seed yield was produced in the CT than in the NT system. Considering the average values from the four-year study period, the seed yield and straw yield, plant density after emergence and before harvest, number of branches and main shoot length, and finally the 1000 seed weight were significantly higher in the CT compared with the NT system. In contrast, the NT system proved more beneficial regarding seed weight per silique and fat content of the seeds. The statistical analysis of the study results showed no effect of the tillage systems on the glucosinolate content of the seeds. In turn, a significantly higher number and air-dry weight of weeds as well as an increased density of Viola arvensis weeds were demonstrated in the NT plot compared with the CT plot of winter oilseed rape. Sonchus asper and Sonchus arvensis were identified in the NT plot but not in the CT plot. A significantly higher density of Chenopodium album and Euphorbia helioscopia weeds was detected in the CT system compared with the NT system. The statistical analysis of study results regarding weed community diversity showed similar values to the Shannon-Weinner diversity index (H’) in both tillage systems and a significantly higher value of the Simpson dominance index (SI) in the NT system compared with the CT system. Full article

Rape undersowing rice is an effective method to solve the problem of short crop rotation in rice-rape rotation. Applying of ground fertilizer to rape is one of the most critical aspects in this planting pattern. However, a special fertilizer spreading is required after the rice is harvested, which increases the labor intensity and the compaction of rape and soil and is also hindered by a lack of equipment to complete the harvesting and fertilizer spreading simultaneously. In response to the above issues, a centrifugal disc spreader on a tracked combine harvester for rape undersowing rice was developed. The basic parameters of the spreader were designed based on the agronomic requirements for fertilization and tracked combine harvester. Kinematic and kinetic models of fertilizer particles were developed to determine the key parameters that affect fertilizer spreading. Based on discrete element simulations, the effects of single structure and interaction of centrifugal disc spreader on fertilizer distribution pattern were investigated. The spreading range and coefficient of variation of fertilizer lateral distribution regression models were constructed, and the spreader parameters were optimized based on the regression models. The simulation results and fertilizer spreading performance were verified by bench tests. The results show that the distribution of fertilizer from simulation tests and bench tests was consistent. The coefficient of variation of fertilizer lateral distribution was 13.1% for the simulation test and 14.6% for the bench test. The error of simulation test was 10.3%, which indicates that the simulation result was reliable. The developed centrifugal disc spreader can meet the needs of fertilizer spreading for rape undersowing rice. The results serve as a theoretical basis for the design of a fertilizer spreader and provide new ways to promote accurate and efficient spreading of fertilizer. Full article

The quality of walnuts deteriorates owing to the poor quality of the shelling equipment. The improvement of shelling quality is urgently required for walnut processing. In this study, systematic research was carried out on the changes in walnut mechanical properties, mechanical model of walnut shelling, and the key parameters of the equipment. The key parameters were determined as the angles of the shelling conic roller (X₁), speeds of the shelling conic roller (X₂), clearance between the shelling conic roller and the static roller (X₃), and the moisture content of walnuts (X₄). The Box–Behnken design method was used for the experimental design, an analysis of variance was applied to determine the graded significance of each variable on the rate of high-quality kernel (RHQK) and rate of shell rushing (RSC), and the multi-objective optimization method was used to obtain the optimal parameters for RHQK and RSC. The ranking of factors affecting RHQK and RSC were: (X₃) > (X₄) > (X₂) > (X₁) for RHQK, and (X₂) > (X₃) > (X₄) > (X₁) for RSC. The ranks of significant interactive effects among the factors were as follows: (X₁ X₂) > (X₂ X₃) for RHQK and (X₂ X₃) > (X₃ X₄) > (X₂ X₄) for RSC. The multi-objective optimization results showed that the optimal combination was $X_1$ = 15.83°, $X_2$ = 17.93 rpm, $X_3$ = 45 mm, and $X_4$ = 9.5%, yielding RHQK = 84.54%, and RSC = 99.15%. The verification test of the optimal results further illustrates the accuracy of the optimization. The obtained results showed that the quality of walnut shelling can be improved by adjusting the moisture content of walnuts and optimizing key parameters of the equipment. This method also represents a potential solution for improving the shelling quality of other nuts. Full article

A recombinant inbred line population, derived from a cross between a high light-tolerant wheat Triticum aestivum cv. Xiaoyan 54 and a high yielding, but high light-sensitive variety, Jing 411, was used to explore the genetic relation between photosynthesis and grain yield-related traits. The net CO₂ assimilation rate, chlorophyll content, chlorophyll a fluorescence parameters, leaf area index, plant height, spike number, biomass, grain yield, and harvest index were evaluated in the field across two consecutive years. The results reveal that a total of 57 quantitative trait loci (QTL) are found to be associated with the investigated traits. They distributed on almost all 21 chromosomes, except for chromosomes 5D, 6D, 7A, and 7D. The phenotypic variance explained by a single QTL ranged from 9.3% to 39.9% depending on traits and QTL. Of these QTL, 12 QTL clusters were found to regulate at least 2 of the investigated traits, which distributed on 8 chromosomes, 1A, 1B, 2A, 2B, 2D, 3A, 3B, 4B and 5A. Seven QTL clusters were associated with both photosynthesis and grain yield-related traits, indicative of their genetic relation. Two QTL clusters on 2D and 4B were co-located with two reduced-height genes, Rht8 and Rht-B1b, respectively. These QTL clusters may be used as potential targets for wheat radiation use efficiency improvement in the future. Full article

Farmers need information on which maize hybrid is best and under what conditions. They demand that this information be clear, simple and easily understood. This study aims to estimate the potential for milk production (MPP) and the biochemical methane potential (BMP) production from fresh maize hybrids. Using these indicators from fresh maize, information on the differences between hybrids can be effectively obtained, albeit with some of the shortcomings of this proposed method. Samples of fresh maize plants (n = 384) from four hybrids were evaluated at two locations over four consecutive years (from 2018 to 2021). The dry matter content, averaged across all hybrids, all years and both locations, was 371 ± 42.3 g.kg⁻¹. The colder and wetter the year, the significantly higher the starch content, lower the amylase-treated neutral detergent fibre content (aNDF) and lower the crude protein (CP), which was reflected in lower BMP. Weather did not significantly affect the net energy of lactation (NEL) or MPP values. The location significantly affected all monitored indicators, except BMP. The earlier the hybrid was at harvest time, the lower the NEL and MPP but the higher BMP contents were. This study is preliminary and must be repeated with more hybrids and under more different conditions. Full article

In tropical areas, the lower productivity of sweet potato has been related to unfavorable climatic conditions, as heat stress caused by high temperatures limits the optimal genotypic expression of plants. Innovative techniques, such as particle films, have been proposed to reduce productivity loss caused by such conditions. Herein, we examine whether applying calcium oxide particle films could minimize heat stress on sweet potato under field conditions, reflecting higher productivity. For this purpose, sweet potato plants were exposed to four concentrations of calcium oxide particle film (0, 5, 10, and 15% w/v) applied onto leaves and assessed regarding the physiological, physicochemical, and productivity parameters. Overall, in plants treated with calcium oxide particle films, the photosynthetic rate, intercellular CO₂ concentration, water use efficiency, and carboxylation efficiency increased compared to untreated plants. Moreover, we observe a reduction in leaf temperature and stomatal conductance of up to 6.8% and 45%, respectively, in sweet potato plants treated with 10% w/v, resulting in higher productivity (34.97 ton ha⁻¹) compared to the control (21.55 ton ha-1). No effect is noted on tuber physicochemical parameters. In summary, the application of a calcium oxide particle film seems to favor sweet potato crops, alleviating the stress caused by hot climatic conditions in tropical regions. Full article

The operation of the semi-automatic pepper pot seedling transplanter has the problem of a low frequency of manual operation. We designed a new automatic transplanting mechanism based on a clamping stem. Through the movement law of a double-crank connecting rod mechanism, the static trajectory of beak shape and the dynamic trajectory of N shape were designed to meet the requirements of backward transplanting. The kinematics equation of the seedling picking mechanism was established and the mechanism parameter optimization program was developed based on MATLAB. The effect of the mechanism parameter changes on the seedling movement trajectory was analyzed. A group of parameter combinations that met the requirements of seedling picking and planting were optimized. After optimization, the trajectory height was 220.8 mm, the picking angle was 21.03° and the planting angle was 64.15°. The plant spacing was 260 mm, which meets the agronomic requirements of pepper transplanting. Through the combination of theoretical analysis and prototype tests, the test results showed that the theoretical trajectory was basically consistent with the actual trajectory, verifying the feasibility of the mechanism design. In this study, pepper pot seedlings in the suitable planting period of 60 days were selected and planted at the rotation speed of 60, 70 and 80 r/min, respectively. The success rate of seedling selection was more than 91.1%, the success rate of planting was more than 78.5%, the qualified rate of erect degree was 94.9%, and the coefficient of variation of plant spacing was stable below 14.1%. The results show that the integrated automatic transplanting mechanism for pepper pot seedlings was effective. Full article

High-molecular-weight glutenin subunits (HMW-GSs) encoded by alleles at the Glu-A1, Glu-B1, and Glu-D1 loci confer unique end-use quality properties of common wheat (Triticum aestivum L.). Wheat accessions with the high-quality HMW-GSs combination of Ax2*/Bx7^OE/Dx5 usually exhibit strong gluten characteristics. In order to stack these three high-quality subunit genes by molecular markers in strong gluten wheat breeding, an agarose gel-based multiplex PCR marker for these high-quality HMW-GSs and two agarose gel-based multiplex PCR markers detecting the homozygosity of Ax2* and Bx7^OE subunits were developed. These markers were verified in an F₂ segregating population from a cross between a medium-gluten winter wheat cultivar with the HMW-GSs combination of Ax null/Bx7 + By8/Dx4 + Dy12 and a strong-gluten spring wheat cultivar with the HMW-GSs combination of Ax2*/Bx7^OE + By8*/Dx5 + Dy10. By integrating the newly established multiplex PCR markers and a published co-dominant PCR marker of the Dx5 subunit, a complete molecular marker selection system was established. After multiple rounds of molecular marker-assisted selection with the system, 17 homozygous winter wheat lines that stacked the three high-quality HMW-GSs were generated. The gluten strength of these homozygous lines was comparable to their strong-gluten parent, but significantly higher than that of their medium-gluten parent by measuring their lactic acid-sodium dodecyl sulfate solvent retention capacities of whole wheat meal. The multiplex PCR systems established in the present study can be used for molecular marker-assisted selection of strong gluten wheats. Full article

Agriculture is in a constant state of change. Its new practices and technologies represent impacts that are difficult to predict. The transition from animal traction to tractors and the substitution of manure for synthetic fertilizers are changes that are taking place particularly in developed countries, yet they are increasing in developing ones. However, the effect of these changes on agriculture and soil CO₂ emissions remains controversial. The objective of this study was to measure the effects of two tillage systems and fertilization on the CO₂ emissions from the soil under maize cultivation. Therefore, it consisted of two tillage systems, namely tractor (T) and animal (A) traction, and four fertilization methods. The fertilization treatments tested were: (CH) application of N, P, K chemical fertilizer; (HM) application of horse manure; (CM) application of chicken manure; and (CT) unfertilized control. We found that the soil CO₂ emission rates in the maize growing season was higher than those in the tillage before the harvest season. Soil respiration peaked in June after the second fertilizer application (9394.59–12,851.35 mg CO₂ m⁻² h⁻¹ at tractor and 7091.89–12,655.86 mg CO₂ m⁻² h⁻¹ at animal traction). The production of corn grain only presented differences between the treatments with and without application of fertilizers. Full article

The present study determines the chemical composition of Schinus molle essential oil and its mortality and repellent effect on Bactericera cockerelli immature stage and Sitophilus zeamais adults. Twenty-four compounds were identified and the most abundant were o-Cymene (29.04), 1R-α-Pinene (15.52), camphene (14.00), and β-myrcene (11.54). On the fifth-instar psyllid nymph, the LC₅₀ and LC₉₀ at 48 h were 442.67 and 864.29 ppm, and for the fourth-instar were 273.41 and 534.67 ppm. The maize-weevil registered an LC₅₀ and LC₉₀ of 343.25 and 986.96 ppm for the fifteenth day. A selection index (Si) of 0.37 with 800 ppm was registered, showing the highest repellent activity, while with the lowest concentration (50 ppm), non-repellent activity was recorded. However, all concentrations above 100 ppm showed repellency against the maize weevil. The study reveals, for the first time, the essential oil’s insecticidal effects on the fourth and fifth nymphal stage of the potato/tomato psyllid B. cockerelli and the usefulness of the essential oil as a repellent against adult of S. zeamais. The Si effect on maize weevil was grouped into categories. Full article

Peach post-harvest ripening is a complex developmental process controlled by a plethora of genetic and epigenetic factors. Specifically, it leads to protein, lipid and nucleic acid degradation, all resulting in cell death. Substantial research has been directed at investigating peach regulatory mechanisms underlying genomic, metabolomic and transcriptomic modifications occurring during this stage, and much progress has been made thanks to the advent of Next Generation Sequencing technologies. This review is focused on the latest multi-omics studies, with the aim of highlighting the most significant results and further investigating the regulation of the key genes involved in peach post-harvest processes and related physiology. By offering an exhaustive overview of peach omics profiles, it provides a comprehensive description of gene expression changes and their correlation with ripening stages, including some post-harvest treatments, as well as with volatile organic compound modifications. However, the present work highlights that, due to the complexity of the process, recent investigations do not elucidate all underlying molecular mechanisms, making further studies still necessary. For this reason, some key points for future research activities and innovative peach breeding programs are discussed, relying on trusted multi-omic approaches. Full article

To solve the problems of poor working conditions and high labor intensity for artificially pruning jujube trees, a pruning scheme using a manipulator is put forward in the present paper. A pruning manipulator with five degrees of freedom for jujube trees is designed. The key components of the manipulator are designed and the dimension parameters of each joint component are determined. The homogeneous transformation of the DH parameter method is used to solve the kinematic equation of the jujube pruning manipulator, and the kinematic theoretical model of the manipulator is established. Finally, the relative position and attitude relationship among the coordinate systems is obtained. A three-dimensional mathematical simulation model of the jujube pruning manipulator is established, based on MATLAB Robotics Toolbox. The Monte Carlo method is used to carry out the manipulator workspace simulation, and the results of the simulation analysis show that the working space of the manipulator is −600~800 mm, −800~800 mm, and −200~1800 mm in the X, Y, and Z direction, respectively. It can be concluded that the geometric size of the jujube pruning manipulator meets the needs of jujube pruning in a dwarf and densely planted jujube garden. Then, based on the high-speed camera technology, the performance test of the manipulator is carried out. The results show that the positioning error of the manipulator at different pruning points of jujube trees is less than 10 mm, and the pruning success rate of a single jujube tree is higher than 85.16%. This study provides a theoretical basis and technical support for the intelligent pruning of jujube trees in an orchard. Full article

Honey bees and beekeeping belong to a large enterprise where the managers are the beekeepers, the workers are the bees, and the products generated are ecosystem goods and services, mostly intangible. Evidence for a reduction in the number of pollinating insects in the planet due to causes that are still being studied has put the spotlight on beekeeping activity and bees (wild and managed) due to their extraordinary capacity to contribute to pollination. The aim of the present work was to detect, identify, and analyze the set of environmental, socioeconomic, and sociocultural utilities (goods and services) generated by honey bees and beekeeping in order to identify possible interrelationships between them. The aim was to demonstrate that these utilities, far from being watertight, are interconnected, which will help to increase their value and highlight their positive externalities (genetic diversity and landscape, among others). This research begins with an overview of some seminal articles, published mainly in the last three years, which were searched following a review using keywords in major databases. After reading the seminal articles and others that were referenced, we analyzed the main utilities generated by honey bees and the possible relationships between them. The main contribution of our results is the determination that the generated utilities are interrelated, which could contribute to increasing their value. In addition, we found that, of the three interrelated dimensions, the socioeconomic dimension encompasses the environmental and sociocultural dimensions. The article ends by proposing future lines of research. Full article

The potato leaf roll virus (PLRV) disease is a serious threat to successful potato production and is mainly controlled by integrated disease management; however, the use of chemicals is excessive and non-judicious, and it could be rationalized using a predictive model based on meteorological variables. The goal of the present investigation was to develop a disease predictive model based on environmental responses viz. minimum and maximum temperature, rainfall and relative humidity. The relationship between epidemiological variables and PLRV disease incidence was determined by correlation analysis, and a stepwise multiple regression was used to develop a model. For this purpose, five years (2010–2015) of data regarding disease incidence and epidemiological variables collected from the Plant Virology Section Ayub Agriculture Research Institute (AARI) Faisalabad were used. The model exhibited 94% variability in disease development. The predictions of the model were evaluated based on two statistical indices, residual (%) and root mean square error (RMSE), which were ≤±20, indicating that the model was able to predict disease development. The model was validated by a two-year (2015–2017) data set of epidemiological variables and disease incidence collected in Faisalabad, Pakistan. The homogeneity of the regression equations of the two models, five years (Y = −47.61 − 0.572x₁ + 0.218x₂ + 3.78x₃ + 1.073x₄) and two years (Y = −28.93 − 0.148x₁ + 0.510x₂ + 0.83x₃ + 0.569x₄), demonstrated that they validated each other. Scatter plots indicated that minimum temperature (5–18.5 °C), maximum temperature (19.1–34.4 °C), rainfall (3–5 mm) and relative humidity (35–85%) contributed significantly to disease development. The foliar application of salicylic acid alone and in combination with other treatments significantly reduced the PLRV disease incidence and its vector population over control. The salicylic acid together with acetamiprid proved the most effective treatment against PLRV disease incidence and its vector M. persicae. Full article

The objective of this study was to examine fluctuations in white clover (Trifolium repens L.) content in perennial ryegrass (Lolium perenne L.) swards within a high nitrogen (250 kg N/ha) input grazing dairy system. The data came from a larger, overall system experiment within which all management and growing condition variables were categorised each year for the 40 paddocks that contained perennial ryegrass-white clover swards, over four growing years. Within that study, eight perennial ryegrass cultivars were examined, each sown individually with two white clover cultivars in a 50:50 mix of ‘Chieftain’ and ‘Crusader’. To determine management associations and meteorological patterns with white clover content and rate/direction of change, separate generalised linear models were used to analyse each individual management or meteorological variable. Paddocks with high white clover contents were associated with lower pre- and post-grazing sward heights, lower pasture cover over the winter period and shorter over-winter period. Perennial ryegrass cultivars with lower pre- and post-grazing height, lower pre-grazing pasture mass and pasture yield removed, all retained more white clover in their swards. Soil fertility remained a key factor that affected white clover persistence influencing the degree of responses in all treatments, particularly soil phosphorus (P) levels. Beyond this, higher white clover contents and lower rates of white clover decline were associated with paddocks that received lower rainfall, had higher soil moisture deficits and received more radiation into the base of the sward, particularly around the time of grazing. Full article

Proline (Pro) is not only an important osmotic adjustment substance, but it also plays an important role in regulating plant abiotic stress resistance. The maize varieties, Xinxin 2 (low temperature insensitive) and Damin 3307 (low temperature sensitive), were chosen as materials, setting a normal temperature for germination (22 °C/10 °C, 9d), low temperature germination (4 °C/4 °C, 5d) and normal temperature recovery (22 °C/10 °C, 4d), combined with a proline (15 mmol·L⁻¹) soaking treatment, to reveal the seed germination and regulation mechanism in maize embryos. The results showed that proline significantly improved the germination potential, germination rate, germination index and vigor index of seeds under low temperature stress, increasing the length of the coleoptile and radicle, increasing the dry and fresh weight of young buds (coleoptile + radicle), and increasing the activity of α-amylase. Proline enhanced the activities of Δ1-pyrroline-5-carboxylic acid synthetase (P5CS) and ornithine aminotransferase (OAT) in maize embryos under low temperature stress, enhanced the proline synthesis pathways, and further enhanced proline accumulation. Proline induced the activity of proline dehydrogenase (ProDH) in the early stage of low temperature stress and stress relief. Under low temperature stress, the activities of hexokinase (HXK), phosphofructokinase (PFK), pyruvate kinase (PK), isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) and glucose-6-phosphate dehydrogenase (G-6-PDH and 6-P-GDH) in maize embryos were decreased, resulting in a decrease in the glycolysis (EMP) pathway, tricarboxylic acid (TCA) cycle and pentose phosphate pathway (PPP). Proline alleviated the inhibition of key enzyme activities of the EMP pathway, TCA cycle and PPP of maize embryos under low temperature stress, increased the activities of cytochrome oxidase (COX) and alternative oxidase (AOX), increased the ATP content, alleviated the inhibition of low temperature stress on main cytochrome pathway activity (ρV_cyt), while further increasing the total respiratory activity (V_t) and the actual operational activity of the alternative pathway (ρV_alt) during seed germination at the initial stage of low temperature stress, as well as improving the inhibition of the V_t and ρV_alt in the middle and late stages of low temperature stress. Under low temperature stress, the content of abscisic acid (ABA) increased significantly, while gibberellin (GA), auxin (IAA) and zeatin nucleoside (ZR) decreased significantly. Proline alleviated the decrease in IAA, ZR and GA contents in maize embryos under low temperature stress, reduced the increase in the ABA content, and reduced the inhibition of low temperature on seed germination. Full article

Solar-induced chlorophyll fluorescence (SIF) has been shown to be a powerful proxy for photosynthesis and a promising indicator of drought monitoring, but the ability of high-resolution satellite-derived SIF for drought monitoring has not been widely investigated due to a lack of data. The lack of high spatiotemporal resolution satellite SIF hinders the resolution enhancement of SIF derived by downscaling or reconstruction algorithms. The TROPOspheric Monitoring Instrument (TROPOMI) SIF provides an alternative with finer spatiotemporal resolution. We present an operational downscaling method to generate 500 m 16-day SIF (TSIF) using Neural Networks over a local spatiotemporal window. The results showed that our method is very robust against overfitting, and TSIF has a strong spatiotemporal consistency with TROPOMI SIF (TROPOSIF) with ${\mathrm{R}}^2=0.956$ and $\mathrm{RMSE}=0.054{\mathrm{mWm}}^{-2}{\mathrm{sr}}^{-1}{\mathrm{nm}}^{-1}$. Comparison with another SIF product (CASIF) showed a spatiotemporal consistency with TSIF. Comparison with tower gross primary productivity (GPP) from AmeriFlux in California showed a strong correlation with ${\mathrm{R}}^2$ for multiple ecosystems ranging from 0.58 to 0.88. We explored the capacity of TSIF for monitoring a drought event in Henan, China, showing that TSIF is more sensitive to drought and precipitation compared to the Enhanced Vegetation Index. Our TSIF is a very promising indicator for regional drought monitoring. Full article

The output intensity of water resources has become a subject of increasing concern. Based on spatial autocorrelation, the Gini coefficient, the Theil index, and geographically and temporally weighted models, this work studied the spatial correlation and regional differences of the output intensity of agricultural water and the main factors influencing the output intensity of agricultural water from a spatial–temporal perspective in China from 2003 to 2019. The results show that the output intensity of agricultural water showed an upward trend and that the output in the central region was higher than the output in the eastern region, and the eastern region had higher output than the western region. By analyzing the spatial autocorrelation, it was found that the output intensity of agricultural water presented a significant spatial dispersion trend and showed the spatial difference. The overall difference in the output intensity of agricultural water in China showed an increasing trend, but the widening difference showed an alleviating trend; the main reason for this increase in the overall differences is that the intra-group differences in the three regions were increasing, with the largest intra-group differences being observed in the western region followed by the eastern region and the central region. Population scale, water use scale, water use structure, effective irrigation scale, urbanization, and industrial structure create significant spatial differences in the output intensity of agricultural water. However, the level of economic development positively impacts the agricultural water output intensity of all provinces. Therefore, water resource management departments should formulate water resource management policies based on regional water conditions and the differences between influencing factors. Full article

Genomic selection (GS) has revolutionized breeding strategies by predicting the rank performance of post-harvest traits via implementing genomic prediction (GP) models. However, predicting pre-harvest traits in unobserved environments might produce serious biases. In soybean, days to maturity (DTM) represents a crucial stage with a significant impact on yield potential; thus, genotypes must be carefully selected to ensure latitudinal adaptation in this photoperiod-sensitive crop species. This research assessed the use of daylength for predicting DTM in unobserved environments (CV00). A soybean dataset comprising 367 genotypes spanning nine families of the Soybean Nested Association Mapping Panel (SoyNAM) and tested in 11 environments (year-by-location combinations) was considered in this study. The proposed method (CB) returned a root-mean-square error (RMSE) of 5.2 days, a Pearson correlation (PC) of 0.66, and the predicted vs. observed difference in the environmental means (PODEM) ranged from −3.3 to 4.5 days; however, in the absence of daylength data, the conventional GP implementation produced an RMSE of 9 days, a PC of 0.66, and a PODEM range from −14.7 to 7.9 days. These results highlight the importance of dissecting phenotypic variability (G × E) based on photoperiod data and non-predictable environmental stimuli for improving the predictive ability and accuracy of DTM in soybeans. Full article

Dry spells in rainfed agriculture lead to a significant reduction in crop yield or to total loss. Supplemental irrigation (SI) with brackish water can reduce the negative impacts of dry spells on net CO₂ assimilation in rainfed farming in semi-arid tropical regions and maintain crop productivity. Thus, the objective of this study was to evaluate the net carbon assimilation rates, indexes for water use efficiency, and indicators of salt and water stress in maize plants under different water scenarios, with and without supplemental irrigation with brackish water. The experiment followed a randomized block design in a split-plot design with four replications. The main plots simulated four water scenarios found in the Brazilian semi-arid region (Rainy, Normal, Drought, and Severe Drought), while the subplots were with or without supplemental irrigation using brackish water with an electrical conductivity of 4.5 dS m⁻¹. The dry spells reduced the photosynthetic capacity of maize, especially under the Drought (70% reduction) and Severe Drought scenarios (79% reduction), due to stomatal and nonstomatal effects. Supplemental irrigation with brackish water reduced plant water stress, averted the excessive accumulation of salts in the soil and sodium in the leaves, and improved CO₂ assimilation rates. The supplemental irrigation with brackish water also promoted an increase in the physical water productivity, reaching values 1.34, 1.91, and 3.03 times higher than treatment without SI for Normal, Drought, and Severe Drought scenarios, respectively. Thus, the use of brackish water represents an important strategy that can be employed in biosaline agriculture for tropical semi-arid regions, which are increasingly impacted by water shortage. Future studies are required to evaluate this strategy in other important crop systems under nonsimulated conditions, as well as the long-term effects of salts on different soil types in this region. Full article

Approximately 50% of the 2600 decommissioned mines in South Korea are implicated in toxic metal/metalloid releases. One of the problems experienced in orchards situated near abandoned mines is the transport of heavy metals including mercury (Hg) into the plants. Due to high levels of Hg observed in orchard soils, heavy metal remediation is needed. The stabilization process is one of the widely used techniques to immobilize heavy metals in contaminated soil and waste. In this study, two types of starfish, Asterias amurensis (ASF) and Asterina pectinifera (PSF), were considered as stabilizing materials for remediating Hg-contaminated soil. In addition to natural starfish, the Hg immobilization effectiveness of calcined forms (CASF and CPSF) was also evaluated comparatively. The effect of particle size reduction on Hg immobilization was assessed for the ASF treatment. Total dosages of less than 10 wt% of ASF and PSF and less than 5 wt% of CASF and CPSF were applied to the Hg contaminated soil. Following treatment and curing for 28 days, the effectiveness of the stabilization process was evaluated using 1N HCl extraction tests. Overall, the stabilization results showed a decrease in Hg leachability with increasing dosages of ASF, PSF, CASF and CPSF. Generally, ASF outperformed the PSF treatments and calcined forms (CASF, CPSF) were more effective than natural forms (ASF, PSF). A reduction of approximately 79% was attained in Hg leachability for the 10 wt% ASF treatments. The -#20 mesh materials were more effective on Hg immobilization than the -#10 mesh materials. The Hg immobilization effectiveness exhibited the following increasing order: PSF (-#10 mesh) < ASF (-#10 mesh) < CPSF (-#10 mesh) < ASF (-#20 mesh) < CASF (-#10 mesh). It was found that effective Hg immobilization was most probably associated with the existing sulfur content in the starfish. The results of scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) indicated that a HgS compound and pozzolanic reaction products were responsible for effective Hg immobilization. Full article

In this paper, a split-flow channel layout with one (group) inlet and two (group) outlets is adopted, based on computational fluid dynamics technology, and compared with the current commonly used channel with one (group) inlet and one (group) outlet emitter. On the premise of the same outlet spacing, the pressure–flow relationship curve and slope of the split-flow emitter were analyzed under the three channel layouts of non-return, single-sided re-entry, and bilateral re-entry, with different channel widths and lengths. When exploring the influence of the channel layout and size on the hydraulic performance of split-flow emitters, the results showed that when the split-flow emitter with a non-return channel is adopted and the hydraulic performance is not reduced, the single-side channel length is half that of the one-in-one-out emitter, meaning the channel width needs to be reduced by 15%. When the channel layout is a single-sided channel re-entry, the hydraulic performance is better than that of the one-in-one-out emitter; if the hydraulic performance of the two remains unchanged, the channel width can be increased by 10% or the single-sided channel length can be reduced by 20%. When the channel layout is a bilateral channel re-entry, the channel width can be increased by nearly 30% if the hydraulic performance of the 2 is consistent, and the single-side channel length is increased by about 50%. When the split-flow emitter adopts a non-return channel layout, the channel width needs to be reduced to ensure the hydraulic performance is consistent. If the layout of single-sided channel re-entry or bilateral channel re-entry is adopted, the hydraulic performance is better than that of the one-in-one-out emitter and the hydraulic performance of the two is consistent. Thus, the channel length can be reduced or the channel width increased, which is beneficial for improving the anti-clogging performance of the emitter. Full article

The objectives of this study were to: (1) assess annual, seasonal and spatial trends in simultaneously extracted metal copper (SEM copper) sediment concentrations in an agricultural California waterbody (Cache Slough) sampled over three years and two seasons (spring and fall); (2) determine the relationship between SEM copper sediment concentrations and precipitation; (3) compare the SEM copper sediment concentrations from Cache Slough with other agricultural streams and (4) compare trends in SEM copper with total copper sediment concentrations previously reported from this waterbody. Sediment samples for SEM copper analysis were collected by boat. Regression analysis, Analysis of Variance, T-test procedure and the Fisher LDS method were used for statistical analysis of data. The results from this study showed that mean seasonal SEM copper sediment concentrations from Cache Slough ranged from 18.6 to 30.1 µg/g dw. SEM copper sediment concentrations were not reported to increase over time in this agricultural waterbody where copper was used as a fungicide, although some spatial differences in SEM copper sediment concentrations were reported. Seasonal analysis showed no significant differences in SEM copper sediment concentrations for both spring and fall for two years, but spring concentrations were statistically higher than fall concentrations for the last year of the study. There were no statistically significant relationships between SEM copper sediment concentrations and precipitation for the three-year period, based on an analysis by year and season. A comparative analysis of total copper and SEM copper from Cache Slough showed that the range of mean seasonal concentrations of SEM copper was much lower, and more sites showed declining trends for SEM copper than for total copper. Increasing trends were not reported at any of the sites for either SEM copper or total copper. A comparison of SEM copper data from Cache Slough was reported to be similar to concentrations reported for other water bodies influenced by agricultural use. Additional multiple year studies in other geographic areas assessing trends in SEM copper sediment concentrations with a comprehensive spatial scale are recommended. Full article

The flow and reallocation of agricultural production factors induced by urbanization play an important role in the changes of the grain production pattern (GPP). Using provincial panel data from 1996 to 2018 in China as the research sample, the center of gravity transfer–standard deviation ellipse model was applied to understand the change characteristics of GPP. Next, a dynamic spatial panel econometric model was established to test the impact of urbanization on GPP, and a spatial mediated effect model was used to identify the mediated transmission paths played by cropland utilization, planting structure adjustment, and agricultural technology progress in this impact process. The main conclusions showed that (1) the grain production COG of China transferred to the northeast, gradually resulting in a spatial pattern from the northeast to the southwest; (2) the urbanization process has a significant negative impact on the GPP, with each unit increase in urbanization resulting in a 0.30% decrease in the grain production concentration index; (3) cropland utilization, planting structural adjustment, and agricultural technology progress play significant mediating roles in the impact of urbanization on the GPP, and their mediating effects can weaken the direct negative impact of urbanization, among which the mediating effect of planting structure adjustment is the highest (13.9%). The study findings provide a new perspective for further understanding the relationship between urbanization and grain production pattern and also provide theoretical references and practical insights for improving the allocation efficiency of agricultural production factors and formulating scientific regional planning policies for grain production in the high-quality transformation of urbanization. Full article