The decline in rice yields as a result of excessive chemical fertilizer (CF) inputs is a matter of great concern in rice-growing regions of Asia. In two-year’s field experiments, the nitrogen, phosphorus, and potassium (NPK) status, growth characteristics and yield of rice were examined by application of poultry manure (PM), cow manure (CM) and compost (CP). Organic fertilizers were applied as EMN (estimated mineralizable N) based on their total N content. Six treatments were assigned in a randomized complete block design: (1) no-N fertilizer (N₀); (2) 50% CF (CF₅₀), (3) 100% CF (CF₁₀₀); 50% CF + 50% EMN from (4) PM or (5) CM or (6) CP. Compared with CF₁₀₀, the CF₅₀PM₅₀ (total N ≥ 4%) accumulated higher N, P and K content in leaf, sheath, panicle and seeds, resulting in greater growth and yield. The CF₅₀PM₅₀ increased yield by 8.69% and 9.70%, dry matter by 4.76% and 5.27% over CF₁₀₀ in both years. The continuous application of CF₅₀CM₅₀ (total N < 4%) and CF₅₀CP₅₀ (total N < 4%) treatments led to similar NPK contents but higher yields than those of CF₁₀₀ treatment in 2018. In conclusion, the organic fertilizer (total N ≥ 4%) with the EMN method enhances higher N availability in each year. Continuous application of organic fertilizer (total N < 4%) over two years effectively increased N availability in the second year. The 50% organic fertilizer (total N ≥ 4%) and 50% CF led to increased NPK availability and rice yields over the 100% CF treatment, reducing CF usage and leading for sustainable agriculture.

When rice is grown under moderate salinity (6 dS m⁻¹), yields are reduced by up to 50%. The development of salt-tolerant varieties is a key strategy for increasing yields. We conducted an experiment using a hydroponic system with ion components similar to seawater to determine useful parameters for assessing salt tolerance. Two-week-old seedlings were grown for 7 days on Yoshida hydroponic solution. The treatment group then additionally received an artificial seawater solution (electrical conductivity, 12 dS m⁻¹). After a 2-week period of salt stress, standard evaluation scores (SES) of visual salt injuries were assessed. The K, Na, Mg, and Ca contents were then determined in the roots, sheaths, and leaves of each plant. Following the SES results, we divided the 37 genotypes into four groups: salt-tolerant groups (STGs), moderately salt-tolerant groups, salt-sensitive groups (HSSGs), and highly salt-sensitive groups (HSSGs). In the control, STGs had the highest sheath K content (30.1 mg g⁻¹ dried weight [DW]), whereas HSSGs had the lowest (21.4 mg g⁻¹ DW). Sheath K was also highly and negatively correlated with SES. This suggests that sheath K may be useful for identifying salt-tolerant varieties under non-saline conditions. Plant growth was significantly affected under salt stress, but STGs had the smallest decrease in sheath DW. SES was significantly correlated with sheath and leaf Na, sheath K and Mg, and sheath and leaf Na/K and Na/Mg ratios. The results suggested that sheath K, Na/K, and Na/Mg may be useful indicators for genetic analyses of salt-tolerant varieties under salt-stress conditions. The salt-tolerant cultivars, KCR20, KCR124, and KCR136, are possible candidates for such studies because they had high sheath K content (31.19, 31.21, 29.44 mg g⁻¹ DW, respectively) under non-saline conditions and low SES (3.3, 3.6, 3.9, respectively), and low sheath Na/K (0.64, 0.52, 0.92, respectively) and Na/Mg ratios (2.96, 2.27, 3.03, respectively) under salt-stress conditions.

A field experiment was conducted to investigate the effects of pretransplant basal (surface application, BSF, and incorporation methods, BIC) and split applications of nitrogen (N) on the growth and yield parameters of rice. Using 120 kg N ha⁻¹ except (N0, control), different percentages of N rate were applied at basal, tillering, and panicle initiation in five N split treatments. Growth parameters and dry matter were greater in BIC than BSF until panicle initiation stages. Among N split applications, N2 (25:50:25) using low basal surface N was optimized for maximum dry matter and yield. With large incorporated basal N, N1 (50:25:25) obtained greater dry matter and yield but did not differ from N4 (50:50:0). With omitted N at tillering, N5 (50:0:50) did not increase rice yield or dry matter by either method. This study highlighted that N split-application patterns affect the growth and yield parameters of Manawthukha rice.

Agricultural by-products can be converted into organic fertilizers through thermophilic composting process. In this study, four combinations of different agricultural by-product materials were composted to find a mixing treatment that improves thermophilic composting process and produces good...

This study aimed to evaluate the effects of chemical and organic fertilizers in different fertilization regimes on vegetative growth, fruit yield, and fruit quality of tomatoes. The experiment was arranged in a randomized complete block design with three replications in the winter season of 2021. The treatments were: no fertilizers, application of NPK fertilizer (15-15-15) at a rate of 1000 kg ha-1, application of chicken manure at a rate of 12 tons ha-1, and three treatments of the combination of NPK fertilizer and chicken manure at the ratios of 70:30, 50:50, and 30:70, respectively. The results indicated that the combination of chemical and organic fertilizers led to improved vegetative plant growth. Combining 70% of NPK fertilizer with 30% of chicken manure gave the maximum fruit yield component values and fruit yield of tomatoes. Adding chicken manure to the fertilization regimes also led to better fruit quality. The integrated fertilization increased the TSS and vitamin C values, and when 50-70% of the chemical fertilizers were substituted with chicken manure, the sugar content and total acid increased in the fruits. The color at the red stage was more intense in tomato fruits treated with the NPK fertilizer and integrated fertilization regimes compared to those from organic fertilization.