This study aims to compare the grain yield, gross return above fertilizer cost (GRAFC: (paddy sales)–(fertilizer cost)), and several parameters relating to the quality of white rice cultivated with different soil-specific nutrient management in 14 provinces where different soil types are distributed. The grain yield tended to increase with increased fertilizer application; however, the relationship between the fertilization rate and the yield was not linear in areas where clay soil dominates. In cases of popular varieties cultivated from the northern to southern province, the amount of fertilizer applied was up to 163 kg ha⁻¹ (sum of N-P₂O₅-K₂O), and the GRAFC and the fertilization rate showed a nonlinear relationship, with a peak of around 120 kg ha⁻¹ fertilization. The nitrogen concentration recognized as a negative factor for the quality of rice tended to increase with an increasing fertilization rate, and the carbohydrate concentration and carbohydrate/protein ratio that are a positive factor for the quality were related negatively with the fertilizer rate. The amylopectin concentration in white rice was positively related with the carbohydrate concentration, which decreased with an increasing fertilization rate. The levels of fertilizer application required to achieve a higher yield, GRAFC, and the maintenance and improvement of parameters relating to grain quality were different. Full article

Improving agricultural research and education is highly recommended to control agricultural development and environmental sustainability in Cambodia. Agricultural research mostly focuses on interviews with farmers as a first measure in developing countries, but a lack of quantitative accuracy remains one of the major constraints. In this situation, we conducted educational activities for master’s degree students of the Royal University of Agriculture (RUA) to append agronomic information with popular equipment in interdisciplinary fieldwork in Pursat Province, Cambodia. For the popular equipment, an RGB camera, a reflectometer as well as pH and EC meters were selected. The agronomic information collected by the students supported the results obtained during the interviews. For example, the difference in fertilizer application between the irrigated and nonirrigated areas was confirmed by the soil ammonium concentration evaluated with a reflectometer; the difference in rice growth among water conditions was confirmed by the leaf area percentage evaluated with an RGB camera. Since the majority of the students lacked agricultural and statistical knowledge, the agronomic information quantified by popular equipment provided proper educational materials. The interdisciplinary fieldwork also indicated serious problems in the study area, such as low beneficial crop production and environmental sustainability. To overcome these problems, improving agricultural education is required to foster skillful agricultural professionals, and the quantification of agronomic information is an essential issue. Full article

Northeast Thailand is the largest rice cultivation region in Thailand, but the rice yield there is quite low. Soil salinity is one of the major yield restricted factors, is derived from underground rock salt, and is predicted to expand in the future. This study focused on evaluating rice productivity related to salinity conditions in Khon Kaen Province, Northeast Thailand. The field investigations were conducted from 2017 to 2019 in farmer fields in severe, moderate, and slight soil salinity classes determined by the Land Development Department of Thailand. The soil salinity on the basis of the electric conductivity of saturated soil extract (ECe) varied year to year, which seemed to be associated with precipitation. The difference in soil salinity between classes was obvious only in the drought year 2018, and reflected in the rice yield, although severe drought devastated rice yield in some fields. Plenty of rainfall may have alleviated soil salinity and rice yield reduction in other years, causing differences in rice yield that were not significant among soil salinity classes. However, salinity level evaluation by the USDA based on ECe showed that rice yield was damaged depending on the level. This study indicates that ECe-based evaluation is recommended for soil salinity in relation to rice productivity. The spatial and temporal evaluation for rice production may benefit farmers. The results in this study also showed rice production largely varied even in similar salinity levels, implying that salinity damage can be alleviated by farmer management. Full article

Illicium difengpi Kib and Kim, an endangered plant unique to karst areas in China, has evolved an extremely high tolerance to arid environments. To elucidate the molecular mechanisms of the response to drought stress in I. difengpi, physiological index determination and transcriptome sequencing experiments were conducted in biennial seedlings grown under different soil moisture conditions (70~80%, 40~50% and 10~20%). With increasing drought stress, the leaf chlorophyll content decreased, while the proline (Pro), soluble sugar (SS) and malondialdehyde (MDA) contents increased; superoxide dismutase (SOD) and peroxidase (POD) activities also increased. Transcriptome sequencing and pairwise comparisons of the treatments revealed 2489, 4451 and 753 differentially expressed genes (DEGs) in CK70~80 vs. XP40~50, CK70~80 vs. XP10~20 and XP40~50 vs. XP10~20, respectively. These DEGs were divided into seven clusters according to their expression trends, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment results of different clusters indicated that genes in the hormone signal transduction and osmotic regulation pathways were greatly activated under mild drought stress. When drought stress increased, the DEGs related to membrane system and protein modification and folding were all upregulated; simultaneously, chitin catabolism- and glycolysis/gluconeogenesis-related genes were continuously upregulated throughout drought stress, while the genes involved in photosynthesis were downregulated. Here, 244 transcription factors derived from 10 families were also identified. These results lay a foundation for further research on the adaptation of I. difengpi to arid environments in karst areas and the establishment of a core regulatory relationship in its drought resistance mechanism. Full article

In order to explore the effect of the relationship between the combination of sowing date and nitrogen application rate on the nitrogen status of rice plants and nitrogen uptake and transfer after anthesis, three sowing dates were set—23 May (S1), 2 June (S2), and 12 June (S3)—and four nitrogen fertilizer treatments—no nitrogen (N0), 180 (N1), 270 (N2), and 360 (N3) kg N/hm²—were applied in a field experiment. The dynamic characteristics of nitrogen in rice post-anthesis under different treatments were analyzed by model fitting. The results showed that the three-leaf SPAD values of rice under different treatments varied, exhibiting a slow–fast–slow inverted S-shaped curve on the days after anthesis. However, the maximum SPAD value (k_s), the time to enter the rapid period of decline (t1_s), and the time to reach the maximum rate (T_s) were different between the different treatments. The maximum SPAD (k_s) values of each sowing date increased with the increase in nitrogen fertilizer application; the t1_s of each treatment was 15–29 days after spike development, and the S3 treatment entered the rapid decline period the earliest. It was beneficial to the transfer of leaf nitrogen to grain, and the nitrogen content, dry matter, and nitrogen uptake of stem sheaths under different treatments varied with days after anthesis; the S3 treatment exhibited the highest values. Leaf nitrogen content and dry matter decreased linearly in different treatments, and leaf nitrogen uptake showed an exponential downward trend. The parameters a_lnc, a_ldm, a_lnu, b_lnc, b_ldm, and b_lnu all increased gradually with the delay in sowing date and the increase in nitrogen, and the maximum values were obtained in the S3N3 treatment. The dry matter accumulation and nitrogen uptake of all treated grains showed a slow–fast–slow S-shaped upward trend over time; the maximum dry matter accumulation (k_gdm) of grains was the greatest at 9652.7 kg/hm², and the duration of the rapid grouting period (t2_gdm − t1_gdm) was the longest, lasting 32 days. The maximum nitrogen absorption of grains (k_gnu) was highest in the S3N3 treatment, whereas the rapid nitrogen absorption duration of grains (t2_gnu − t1_gnu) was the longest in S1N0. These results provide a basis for the development of optimized nitrogen fertilizer application, real-time nitrogen fertilizer management, and post-anthesis nitrogen uptake and distribution models for rice with different sowing dates. Full article

Agricultural activities cannot be separated from indigenous knowledge (IK), which has developed and continues to be strongly maintained by Bugis–Makassar farmers in the face of rapidly developing science and technology. The objective of this study was to explore the IK practices in rice cultivation of the Bugis–Makassar farmer community, as well as the process of integrating IK and scientific knowledge into decision making. The study used a number of qualitative methodologies to gather information, including meetings, focus group discussions, in-depth interviews, and semi-structured interviews. Our results show that IK is slowly disappearing and being replaced by middle-aged people and youth, who seem to care more about modernization than assimilation. However, with the existence of Tudang Sipulung, the fading of local wisdom may be inhibited. Tudang Sipulung’s strength lies in the government’s involvement in integrating IK and scientific knowledge into formal forums and agreement. The Tudang Sipulung agreement is formally binding with constitutional sanctions applied. In order to provide optimum benefits, engaging young farmers in the understanding and preservation of indigenous and scientific knowledge is recommended to preserve local culture and transfer modern technology. Full article

Sengon (Falcataria moluccana), a fast-growing timber tree that naturally grows on mineral soils, is currently promoted in peatlands. This study aimed to (1) experimentally test the response of sengon seedlings in waterlogged conditions in the nursery; (2) describe and analyze the biophysical condition of a sengon plantation and its growth; (3) describe sengon farm practices on peatlands; and (4) identify key actor’s perception on planting sengon on peatlands. This study combined an experiment in nursery, field measurements, and key-informant interviews. The nursery experiment showed that peat soil affected seedling’s growth: survival rates decreased by 25–33% after 3 months of inundation. Sengon growth at age 1–5-years-old in peat soil was slower than that on mineral soils. Sengon growth in peatland was influenced by peat depth and peat maturity. Sengon plantation in Central Kalimantan was driven by market availability and industrial wood demand. Fourty-three percent of respondents thought sengon does not grow well in peat soils, but 57% of respondents thought that additional soil treatment will enhance site suitability. Based on key-informants’ experience, 64% disagree with sengon development in peatlands. Our study provides evidence that sengon is predominantly not suitable to be planted on peatlands. Therefore, cautions need to be taken when planting sengon on peatland areas. Full article

Climate change and its variability are some of the most critical threats to sustainable agriculture, with potentially severe consequences on Indonesia’s agriculture, such as changes in rainfall patterns, especially the onset of the wet season and the temporal distribution of rainfall. Most Indonesian farmers receive support from agricultural extension services, and therefore, design their agricultural calendar based on personal experience without considering global climate phenomena, such as La Niña and El Niño, which difficult to interpret on a local scale. This paper describes the Integrated Cropping Calendar Information System (ICCIS) as a mechanism for adapting to climate variability. The ICCIS contains recommendations on planting time, cropping pattern, planting area, varieties, fertilizers, agricultural machinery, potential livestock feed, and crop damage due to climate extremes for rice, maize, and soybean. To accelerate the dissemination of information, the ICCIS is presented in an integrated web-based information system. The ICCIS is disseminated to extension workers and farmers by Task Force of the Assessment Institute for Agricultural Technology (AIAT) located in each province. Based on the survey results, it is known that the ICCIS adoption rate is moderate to high. The AIAT must actively encourage and support the ICCIS Task Force team in each province. Concerning the technological recommendations, it is necessary to update the recommendations for varieties, fertilizer, and feed to be more compatible with local conditions. More accurate information and more intensive dissemination can enrich farmers’ knowledge, allowing for a better understanding of climate hazards and maintaining agricultural production. Full article

An agricultural waste-based source of energy in the form of briquettes from rice husk has emerged as an alternative energy source. However, rice husk-based briquette has a low bulk density and moisture content, resulting in low durability. This study investigated the effect of initial moisture contents of 12%, 14%, and 16% of rice husk-based briquettes blended with 10 wt% of kraft lignin on their chemical and physical characteristics. The briquetting was done using a hand push manual die compressor. The briquette properties were evaluated by performing chemical (ultimate and proximate analysis, thermogravimetric analysis), physical (density, durability, compressive strength, and surface morphology) analyses. The durability values of all briquette samples were above 95%, meeting the standard with good compressive strength, surface morphology, and acceptable density range. The briquette made from the blend with 14% moisture content showed the highest calorific value of 17.688 MJ kg⁻¹, thanks to its desirable morphology and good porosity range, which facilitates the transport of air for combustion. Overall, this study proved the approach of enhancing the quality of briquettes from rice husk by controlling the moisture content. Full article

This study reports the development of bio-based adsorbent by utilizing coffee endocarp (CE) waste as a raw material for lead (Pb) removal from liquid wastewater. The effect of NaOH and HCl as activation precursors on the characteristics and performance of the resulting adsorbents was investigated. The prepared adsorbents were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF) and Surface Area Analyzer (SAA). The characterization results confirm the positive role of the activation by either NaOH or HCl in enhancing the surface properties of the resulting adsorbents. The chemical activations removed most of impurities leading to smoother surface, pore size enlargement and enhanced surface area to pore volume ratio, which result in an enhanced adsorption capacity and Pb removal efficiency. The raw adsorbent shows 57.7% of Pb removal efficiency and sorption capacity of 174.4 mg/g. On the other hand, after the chemical treatment using HCl and NaOH, the Pb removal efficiencies increased up to 63.9% and 89.86%, with adsorption capacity of 193 and 271.58 mg/g, respectively. Though both activated sorbents demonstrate better adsorption performance compared to the non-activated CE, overall results reveal that the NaOH-activated sorbent offers better characteristic and performance than the HCl-activated sorbent. Full article

Sloping farmland is prevalent in hilly red soil areas of South China. Improper tillage patterns induce decreased soil organic matter, soil aggregate breakdown, and nutrient imbalance, thereby restricting crop production. However, the stoichiometric characteristics could reflect the nutrient availability which was mostly studied on bulk soil. The stoichiometric characteristics of soil aggregates with multiple functions in farmlands has rarely been studied. The study was to reveal the impact of tillage patterns on the size distribution, nutrient levels, and stoichiometric ratios of soil aggregates after 20 years’ cultivation. Soil samples of 0–20 cm and 20–40 cm from five tillage patterns, bare-land control (BL), longitudinal-ridge tillage (LR), conventional tillage + straw mulching (CS), cross-ridge tillage (CR), and longitudinal-ridge tillage + hedgerows (LH) were collected. The elemental content (C, N and P) and soil aggregate size distribution were determined, and the stoichiometric ratios were subsequently calculated. Through our analysis and study, it was found that the nutrient content of >2 mm soil aggregates in all plots was the highest. In the hedgerow plots, >2 mm water-stable soil aggregate content was increased. Therefore, LH plots have the highest content of organic matter and nutrients. After 20 years of cultivation, stoichiometric ratio of each plot showed different changes on soil aggregates at different levels. the C:N, C:P, and N:P ratios are lower than the national average of cultivated land. Among of them, the stoichiometric ratio in the LH plot is closer to the mean and showed better water-stable aggregate enhancement. Therefore, longitudinal-ridge tillage + hedgerows can be recommended as a cultivation measure. This study provides a reference for determining appropriate tillage measures, balancing nutrient ratios, and implementing rational fertilization. Full article

Regulation of non-structural carbohydrates (NSCs) are important for plants in response to submergence. In this study, the difference in non-structural carbohydrates in relation with shoot elongation between Sub1A and non-Sub1A rice genotypes was investigated. Two rice genotypes, namely Inpari30 (Sub1A genotype) and IR72442 (non-Sub1A genotype), were submerged completely for 6 days and re-aerated by lowering water level up to stem base for 6 days of post submergence. In addition, non-submerged plants (control) was treated with water level up to stem base during the experiment. Photosynthesis rate decreased in both submerged Inpari30 and IR72442 genotypes 71% and 96% lower than their control, respectively. Submerged IR72442 declined Fv/Fm 15.6% lowest than its control and both control and submerged Inpari30. Investigation of the distribution of starch and soluble sugar content in plant organs suggested that shoot elongation of non-Sub1A genotype led to starch and sugar consumption that distributed faster to the new developed organ during submergence. In contrast, Sub1A genotype of Inpari30, which did not exhibit shoot elongation and showed slower NSCs distribution during submergence, performed better on post submergence by maintaining NSCs and distributing to the new developed organ faster than IR72442. These results suggest that Sub1A genotype managed elongation and NSCs during submergence more efficiently than non-Sub1A genotype. Full article