G S Yadav

A Review of Organic Farming for Sustainable Agriculture in Northern India

In the post independence period, the most important challenge in India has been to produce enough food for the growing population. Hence, high-yielding varieties are being used with infusion of irrigation water, fertilizers, or pesticides. This combination of high-yielding production technology has helped the country develop a food surplus as well as contributing to concerns of soil health, environmental pollution, pesticide toxicity, and sustainability of agricultural production. Scientists and policy planners are, therefore, reassessing agricultural practices which relied more on biological inputs rather than heavy usage of chemical fertilizers and pesticides. Organic farming can provide quality food without adversely affecting the soil’s health and the environment; however, a concern is whether large-scale organic farming will produce enough food for India’s large population. Certified organic products including all varieties of food products including basmati rice, pulses, honey, tea, spices, coffee, oilseeds, fruits, cereals, herbal medicines, and their value-added products are produced in India. Non edible organic products include cotton, garments, cosmetics, functional food products, body care products, and similar products. The production of these organic crops and products is reviewed with regard to sustainable agriculture in northern India.

Response and interaction of Bradyrhizobium japonicum and arbuscular mycorrhizal fungi in the soybean rhizosphere

Regulatory response and interaction of Bradyrhizobium and arbuscular mycorrhizal fungi (AMF) play a vital role in rhizospheric soil processes and productivity of soybean (Glycine max L.). Nitrogen (N) and phosphorus (P) are essential nutrients for plant growth and productivity, the synergistic interaction(s) of AMF and Bradyrhizobium along with rhizospheric beneficial microorganisms stimulate soybean growth and development through enhanced mineral nutrient acquisition (N and P) and improved rhizosphere environment. Such interactions are crucial, especially under low-input eco-friendly agricultural cropping systems, which rely on biological processes rather than agrochemicals to maintain soil quality, sustainability, and productivity. Furthermore, enhancement of N-fixation by root nodules along with AMF-mediated synergism improves plant P nutrition and uptake, and proliferation of phosphate-solubilizing fungi. However, the genetic and/or allelic diversity among native strains, their genes/enzymes and many environmental factors (e.g., soil organic matter, fertilizers, light, temperature, soil moisture, and biotic interactors) affect the interactions between AMF and Bradyrhizobium. New information is available regarding the genetic composition of elite soybean inoculant strains in maximizing symbiotic performance, N-fixing capabilities and depending on N and P status the host-mediated regulation of root architecture. Overall, for sustainable soybean production systems, a deeper understanding of the interaction effects of Bradyrhizobium and AMF co-inoculation are expected in the future, so that optimized combinations of microorganisms can be applied as effective soil inoculants for plant growth promotion and fitness. The objective of this review is to offer insights into the mechanistic interactions of AMF and Bradyrhizobium and rhizopheric soil health, and elucidate the role of environmental factors in regulating growth, development and sustainable soybean productivity.

A Review on Recycling of Sunflower Residue for Sustaining Soil Health

Modern agriculture is now at the crossroads ecologically, economically, technologically, and socially due to soil degradation. Critical analysis of available information shows that problems of degradation of soil health are caused due to imbalanced, inadequate and promacronutrient fertilizer use, inadequate use or no use of organic manures and crop residues, and less use of good quality biofertilizers. Although sizeable amount of crop residues and manure is produced in farms, it is becoming increasingly complex to recycle nutrients, even within agricultural systems. Therefore, there is a need to use all available sources of nutrients to maintain the productivity and fertility at a required level. Among the available organic sources of plant nutrients, crop residue is one of the most important sources for supplying nutrients to the crop and for improving soil health. Sunflower is a nontraditional oil seed crop produced in huge amount of crop residue. This much amount of crop residues is neither used as feed for livestock nor suitable for fuel due to low energy value per unit mass. However, its residue contains major plant nutrients in the range from 0.45 to 0.60% N, 0.15 to 0.22% P, and 1.80 to 1.94% K along with secondary and micronutrients, so recycling of its residue in the soil may be one of the best alternative practices for replenishing the depleted soil fertility and improving the physical, chemical, and biological properties of the soil in the present era of production. However, some researchers have reported allelopathic effects of sunflower residue on different crops. So, selection of suitable crops and management practices may play an important role to manage the sunflower residue at field level.

Bacterial inoculation effect on soil biological properties, growth, grain yield, total phenolic and flavonoids contents of common buckwheat (Fagopyrum esculentum Moench) under hilly ecosystems of North-East India

Field experiments were carried out at Research Farm, ICAR Sikkim Centre, Tadong during two consecutive Rabi seasons of 2012 and 2013 to determine the effect of different microbial inoculants on selected soil biological properties, growth, yield, and quality of common buckwheat, and then identify the best inoculant for application for local common buckwheat production in hilly ecosystem of North-East India. The results indicated that seed inoculants applied to common buckwheat effectively increased plant growth, chlorophyll content (SPAD), yield attributing characters, total phenolic and flavonoid content, grain yield, and soil biological properties. Among the different inoculations, combined application of Azotobacter spp. and Azospirillum spp. was found most efficient and resulted in maximum values of plant growth parameter, yield attributing characteristics, grain yield (1.23 Mg/ha), soil microbial biomass carbon (SMBC) and dehydrogenase activities at all the growth stages of common buckwheat. Key words: Buckwheat, dehydrogenase activities, flavonoid content, phenolic content, microorganisms, yield.

Influence of tillage and organic nutrient management practices on productivity, profitability and energetics of vegetable pea (Pisum sativum L.) in rice-vegetable pea sequence under hilly ecosystems of north-east India

Fixed plot field experiments were conducted at Research Farm, ICAR Sikkim Centre during 2013–14 and 2014–15 to identify the efficient tillage practices and organic nitrogen sources for achieving higher productivity, profitability and energy use efficiency of vegetable pea (Pisum sativum L.) in rice-vegetable pea cropping system of eastern Himalayas. Pooled data of two years showed that among the tillage practices, significantly higher values of yield attributes viz., pod length (8.3 cm), pods/plant (9.9), pod weight (8.3 g), green pea seeds/pod (8.0) and yields [green pod yield (5.89 t/ha) and stover yield (7.49 t/ha)] were recorded with no-tillage (NT) over reduced tillage (RT) and conventional tillage (CT). Similarly, significantly higher gross returns (125.4 x 103Rs./ha), net returns (96.1 x 103Rs./ha) and B: C ratio (3.27) were recorded with NT over RT and CT. Energy use efficiency was also significantly higher with NT (6.29%) over RT (4.29%) and CT (3.12%). NT required 44 and 28.3% less energy as compared to CT and RT, respectively. Amongst the organic nitrogen sources, significantly higher values of yield attributing characters, green pod yield (6.33 t/ha) and stover yield (6.67 t/ha) were recorded with the application of 50% RDN (recommended dose of nitrogen) through FYM+50% RDN through VC (vermicompost)+BF (biofertilizer) over other organic nitrogen sources. This resulted in 24.9% enhancement in green pod yield over the farmers practices. In terms of profitability and energetics, application of 50% RDN through FYM+50% RDN through VC+BF was found statistically superior to others and recorded 29.5% higher net returns and 9.9% higher energy use efficiency over the farmers practice (FYM @ 1.0 t/ha) of the region.

Conservation tillage and mulching effects on the adaptive capacity of direct-seeded upland rice (Oryza sativa L.) to alleviate weed and moisture stresses in the North Eastern Himalayan Region of India

ABSTRACT A field experiment was conducted to study the effects of tillage and mulch on weed growth, soil moisture storage, productivity and profitability of upland rice during 2012–2013 at Lembucherra, India. Tillage treatments included CT-RI: conventional tillage with 100% residue incorporation and NT-RR: no-till with 100% residue retention. Mulches included rice straw (SM), Gliricidia (GM), brown manuring (BM) and none (NM). CT-RI registered the highest total weed density (89–168 weeds m−2) and biomass (9.6–183 g dry weight m−2) than those for the NT-RR (75–161 weed m−2 and 8–155 g dry weight m−2). In addition, NT-RR stored (122–172 mm) more soil moisture (0–40 cm soil depth) in comparison with that for the CT-RI treatment (110–161 mm) during crop growing season. Tillage treatments did not have the significant effect on yields. NT-RR reduced the cost of cultivation by 31.5% compared with that for the CT-RI. Thus, the net returns under NT-RR were more than those for the CT-RI. The BM recorded the lowest weed biomass and density as compared to that under other mulches. Therefore, cultivation of upland rice using NT along with BM mulching enhanced productivity and profitability of rice cultivation in India.

Effect of organic nitrogen sources on growth, yield, quality, water productivity and economics of rice (Oryza sativa L.) under different planting methods in mid-hills of Sikkim Himalayas

In order to evaluate the effect of organic sources of nitrogen on growth, yield, water productivity and economics of rice under different methods of planting in hilly ecosystems of north-east India, an experiment was carried out in kharif seasons of 2013 and 2014 in split plot design with three replications. The results revealed that SRI recorded significantly higher values for all growth parameters (plant height, dry matter accumulation, leaf area index, flag leaf length, tillers/m2, root volume and root dry weight), yield attributing characters (productive tillers/m2, panicle length, grains/panicle, filled grains/panicle and test weight), water productivity (kg grain/m3 of water), grain yield and economics over the CP. This caused 36.84 and 29.41, 34 and 28, 60.0 and 55.3% improvement in water productivity, grain yield and net returns over the CP during 2013 and 2014, respectively. Among the organic sources of nitrogen, application of 25% RDN through FYM+25% RDN through VC+25% RDN through PM+25% RDN through MC significantly enhanced the growth, yield attributing characters, water productivity (0.26 and 0.23 kg of grain/water m3), grain yield (3.53 and 3.41 t/ha), net returns (88 x 103 and 83 x 103 Rs./ha) and B: C ratio (1.84 and 1.74) in 2013 and 2014, respectively.