RESUMO
During the summer and rainy seasons (April-October) of 2020 and 2021, two consecutive field experiments were conducted at the research farm of the ICAR-Indian Agricultural Research Institute, New Delhi, India. In this study, we examined the effects of summer green manuring crops (GM) and a variety of zinc fertilizers (ZnF) on Basmati rice (Oryza sativa L.) growth, physiological development, yield response, zinc nutrition and economic returns. A combination of GM residues and nano zinc fertilization helped significantly enhancing Basmati rice's growth and its physiological development. Following the incorporation of Sesbania aculeata (Sesbania), successive Basmati rice physiological parameters were significantly improved, as well as grain, straw, biological yields, harvest index and economic returns. The highest Zn content of 15.1 mg kg -1 and the lowest of 11.8 mg kg -1 in milled rice grain were recorded in Sesbania green manuring (G2) and control i.e., in the fallow (G1), respectively. Coating onto urea with 0.2% nano zinc oxide (NZnCU) was observed to be more effective than other zinc sources in terms of growth parameters, yield attributes, zinc nutrition, grain and straw yields for succeeding Basmati rice crop; however, the effects were comparable to those of bulk zinc oxide-coated urea (BZnCU) of 1%. The highest Zn content of 15.1 mg kg -1 was recorded with the application of 1% BZnCU and the lowest of 11.96 mg kg -1 with the soil application of 5 kg Zn ha -1 through bulk ZnO in the milled rice grain. Application of 1% BZnCU led to a 26.25% increase in Zn content of milled rice grain compared to soil application of 5 kg Zn ha -1 through bulk ZnO. As a result, the combination of inclusion of Sesbania aculeata (Sesbania) residue and 0.2% NZnCU was identified as the most effective treatment, for Basmati rice growth and physiological development. A combination of nano Zn fertilization in conjunction with the incorporation of green manure can be advocated for better growth, physiological performance, zinc dense grains, and higher profitability of Basmati rice for farmers and consumers.
RESUMO
Harnessing the benefits of plant-microbe interactions towards better nutrient mobilization and plant growth is an important challenge for agriculturists globally. In our investigation, the focus was towards analyzing the soil-plant-environment interactions of cyanobacteria-based formulations (Anabaena-Nostoc consortium, BF1-4 and Anabaena-Trichoderma biofilm, An-Tr) as inoculants for ten maize genotypes (V1-V10). Field experimentation using seeds treated with the formulations illustrated a significant increase of 1.3- to 3.8-fold in C-N mobilizing enzyme activities in plants, along with more than five- to six-fold higher values of nitrogen fixation in rhizosphere soil samples. An increase of 22-30% in soil available nitrogen was also observed at flag leaf stage, and 13-16% higher values were also recorded in terms of cob yield of V6 with An-Tr biofilm inoculation. Savings of 30 kg N ha-1 season-1 was indicative of the reduced environmental pollution, due to the use of microbial options. The use of cyanobacterial formulations also enhanced the economic, environmental and energy use efficiency. This was reflected as 37-41% reduced costs lowered GHG emission by 58-68 CO2 equivalents and input energy requirement by 3651-4296 MJ, over the uninoculated control, on hectare basis. This investigation highlights the superior performance of these formulations, not only in terms of efficient C-N mobilization in maize, but also making maize cultivation a more profitable enterprise. Such interactions can be explored as resource-conserving options, for future evaluation across ecologies and locations, particularly in the global climate change scenario.