Hanuman S. Jat

Assessing soil properties and nutrient availability under conservation agriculture practices in a reclaimed sodic soil in cereal-based systems of North-West India

ABSTRACT Soil quality degradation associated with resources scarcity is the major concern for the sustainability of conventional rice-wheat system in South Asia. Replacement of conventional management practices with conservation agriculture (CA) is required to improve soil quality. A field experiment was conducted to assess the effect of CA on soil physical (bulk density, penetration resistance, infiltration) and chemical (N, P, K, S, micronutrients) properties after 4 years in North-West India. There were four scenarios (Sc) namely conventional rice-wheat cropping system (Sc1); partial CA-based rice-wheat-mungbean system (RWMS) (Sc2); CA-based RWMS (Sc3); and CA-based maize-wheat-mungbean (Sc4) system. Sc2 (1.52 Mg m−3) showed significantly lower soil bulk density (BD). In Sc3 and Sc4, soil penetration resistance (SPR) was reduced and infiltration was improved compared to Sc1. Soil organic C was significantly higher in Sc4 than Sc1. Available N was 33% and 68% higher at 0–15 cm depth in Sc3 and Sc4, respectively, than Sc1. DTPA extractable Zn and Mn were significantly higher under Sc3 and Sc4 compared to Sc1. Omission study showed 30% saving in N and 50% in K in wheat after four years. Therefore, CA improved soil properties and nutrient availability and have potential to reduce external fertilizer inputs in long run.

Can productivity and profitability be enhanced in intensively managed cereal systems while reducing the environmental footprint of production? Assessing sustainable intensification options in the breadbasket of India

Highlights • Higher cereal productivity can be achieved with lower environmental footprint through conservation agriculture.• Wheat productivity and profitability can be increased by zero-tillage and early sowing.• Kharif maize appears to be a suitable and profitable alternative to rice in northwest India.• Productivity and resource efficiency of transplanted rice can be improved by BMPs.• Directly sown rice has potential to save water, energy and global warming potential compared to transplanted rice.

Crop residue degradation by fungi isolated from conservation agriculture fields under rice–wheat system of North-West India

PurposeIn North West-Indo Gangetic Plains (NW-IGP) of India in situ burning of crop residues is practiced by majority of farmers’ which deteriorates soil and environmental quality. Fungi have the potential for lignocellulose degradation and can be used for the in situ decomposition of crop residues. Lignocellulose degrading fungal spp. were isolated and evaluated for the activity of lignocellulolytic enzymes.MethodThe lignocellulose degrading fungi were isolated by appearance of zone on carboxy methyl cellulose (CMC) agar media and tannic acid (TA) media. Carboxy methyl cellulase, filter paperase, cellobiase, xylanase and laccase activity were estimated in submerged, as well as solid state fermentation using a mixture of rice and wheat straw in the ratio of 4:1. rice–wheat straw as substrate. The residue left after solid state fermentation was evaluated for carbon/nitrogen ratio, dry mass loss, and loss of cellulose, hemicellulose and lignin. Selected potential isolates were further tested in pot experiment for their effect on wheat plants. The interaction among isolates was also studied.ResultAfter primary screening, 19 out of a total of 72 fungal isolates were selected based on their enzymatic activity profile and potential to degrade lignocellulosic residues in submerged fermentation. Out of these 19 isolates, 11 were further selected based on their enzymatic secretions in solid state fermentation. All the 11 strains were identified morphologically. Four fungal isolates (RPW 1/3, RPW 1/6, RPWM 2/2 and RZWM 3/2) showed higher enzymatic activities and more loss of dry mass and cell wall constituents over the other isolates. These isolates were identified by ITS region sequencing as Aspergillus flavus, Aspergillus terreus, Penicillium pinophilum and Alternaria alternata.ConclusionThis study revealed that fungal isolates may be used for managing crop residues in conservation agriculture based rice–wheat system of NW-IGP to eliminate ill effects of residue burning.

Soil bacterial diversity under conservation agriculture-based cereal systems in Indo-Gangetic Plains

In Indo-Gangetic plains (IGP) of India, natural resources (soil, water, and environment) are degrading under the conventional–till (CT)-based management practices in rice–wheat cropping system. A long-term field experiment was conducted to understand the soil bacterial diversity and abundance under different sets of management scenarios (Sc). The study comprised of four scenarios, namely, -Sc.I CT-based rice–wheat system (farmers’ practice); Sc.II, partial conservation agriculture (CA) based in which rice is under CT—wheat and mungbean under zero-tillage (ZT); Sc.III, full CA-based in which rice–wheat–mungbean are under ZT and Sc.IV, where maize–wheat–mungbean are under ZT. These scenarios varied in cropping system, tillage, and crop residue management practices. Using Illumina MiSeq sequencing technology, the variable regions V3–V4 of 16S rRNA were sequenced and the obtained reads were analyzed to study the diversity patterns in the scenarios. Results showed the presence of 53 bacterial phyla across scenarios. The predominant phyla in all scenarios were Proteobacteria, Acidobacteria, Actinobacteria, and Bacteroidetes which accounted for more than 70% of the identified phyla. However, the rice-based systems (Sc.I, Sc.II, and Sc.III) were dominated by phylum Proteobacteria; however, maize-based system (Sc.IV) was dominated by Acidobacteria. The class DA052 and Acidobacteriia of Acidobacteria and Bacteroidetes of Bacteroidia were exceptionally higher in Sc.IV. Shannon diversity index was 8.8% higher in Sc.I, 7.5% in Sc.II, and 2.7% in Sc.III compared to Sc.IV. The findings revealed that soil bacterial diversity and abundance are influenced by agricultural management practices as bacterial diversity under full CA-based management systems (Sc.III and Sc.IV) was lower when compared to farmer’s practice (Sc.I) and partial CA (Sc.II) scenarios.

Diversity of Wild Edible Mushrooms in Indian Subcontinent and Its Neighboring Countries

Mushrooms are cosmopolitan heterotrophic organisms that are quite specific in their nutritional and ecological requirements. They are among the most relished food commodities among a number of nonconventional foodstuffs primarily because of their unique flavor and texture. Wild edible mushrooms have been collected and consumed by people since thousands of years. Mushrooms have been exploited commercially the world over. In India due to its diverse climatic conditions, many types of mushrooms are found in the wild. The knowledge of their historical uses as food, medicine, a source of income, and for small-scale businesses and the sociological impacts (myth, culture, and spirituality) are apparently threatened due to slow ethnomycology-research drive.