Search

Food security worldwide is largely dependent on the rice–wheat cropping sequence (RWCS) Hence, a field study was carried out during 2018–19 and 2019–20 at ICAR-IARI, New Delhi, to determine the effect of various enriched organic sources and crop establishment methods on the root parameters, water productivity and yield of rice, its carryover effect on the succeeding wheat crop and the overall efficiency of system. A split plot design was used which involved two main plot treatments, viz., aerobic rice (AR) and conventional transplanted (CT) rice, and five subplot treatments, viz., T1: control (without fertilizer), T2: 100 % RDF (100 % fertilization by using inorganic sources), T3: 50 % phosphorus was applied by using P-enriched compost + 50 % P was applied by using DAP, T4: 50 % N was applied by using N-enriched compost + 50 % nitrogen was applied by using DAP and urea, and T5: 100 % organic fertilizer was applied (100 % fertilization by using N-enriched compost and P-enriched compost). After rice, wheat was grown in all the plots under uniform management practices. Among the nutrient sources, T4 had greater effects on root activity, system economic water productivity and system water productivity than did the other treatments. CT rice can be recommended under irrigated conditions with the integration of enriched compost and inorganic fertilizers. However, under rainfed conditions with less available water, aerobic rice can also be produced by combining enriched compost and inorganic fertilizer.

Drought and cadmium (Cd) stress are both major issues that significantly affect the growth and development of wheat plants. Both drought stress and Cd toxicity disrupt physiological processes i.e., nutrient uptake, cell expansion, and enzymatic reactions resulting in poor crop growth. To overcome these issues, the use of activated carbon and gibberellic acid (GA3) are considered valuable amendments. However, the current study aimed to add value using GA3-enriched biochar (GA3-BC). That's why, a lab experiment was conducted on wheat to assess the effectiveness of GA3-BC against Cd and drought stress. For GA3 enrichment in biochar, 10 µg GA3/g biochar was mixed. There were 3 levels of GA3-BC i.e., 0, 0.6 (GA3-BC1), and 0.9% (GA3-BC). All levels were applied in 3 replicates under no stress (0Cd + no drought), drought stress (DS), and 6 mg Cd/ kg soil (6Cd). Results showed that GA3-BC2 caused a significant improvement in shoot length (44.99%), root length (99.73%), seedling length (60.13%) and shoot fresh weight (63.59%) over control at 6Cd + drought stress. A significant improvement in chlorophyll a, chlorophyll b, and total chlorophyll while a decrease in electrolyte leakage and regulation of antioxidants i.e., lipid peroxidation, SOD, CAT, APx, GR, GPx, GST, and DPHH also signified the effectiveness of GA3-BC2 compared to control at 6Cd + drought stress. In conclusion, GA3-BC2 is an efficacious amendment for simultaneously alleviating drought and Cd stress in wheat. More investigations are recommended at the field level on different cereal crops cultivated in different soil textures to declare GA3-BC2 as the best treatment for mitigation of drought stress and Cd toxicity. [ABSTRACT FROM AUTHOR]