Soil aggregation and carbon and nitrogen stabilization in relation to residue and manure application in rice–wheat systems in northwest India

Abstract

Soil organic matter (SOM), besides influencing carbon (C) transfer between soils and atmosphere, impacts soil functional ability and its response to environmental and anthropogenic influences. We studied the impact of continuous application of rice straw and farmyard manure (FYM) either alone or in conjunction with inorganic fertilizers on aggregate stability and distribution of C and nitrogen (N) in different aggregate fractions after 7 years of rice-wheat cropping on a sandy loam soil. Macroaggregates ([0.25 mm) constituted 32.5-54.5% of total water stable aggregates (WSA) and were linearly related (R 2 = 0.69) to soil organic carbon content. The addition of rice straw and FYM significantly (P \ 0.05) improved the formation of macroaggregates with a concomitant decrease in the proportion of microaggregates at all the three sampling depths (0-5, 5-10 and 10-15 cm). Macroaggregates had higher C and N density as compared to microaggregates. Application of rice straw and FYM improved C and N density in different aggregate sizes and the improvement was greatest in plots that received both rice straw and FYM each year. Application of FYM along with inorganic fertilizer resulted in a net C sequestration of 0.44 t ha -1 in the plough layer after 7 years of rice-wheat cropping. Carbon sequestration was greater (1.53 t ha -1 ) when both rice straw and FYM along with inorganic fertilizers were applied annually. It is concluded that addition of rice straw and FYM in rice-wheat system improves soil aggregation and enhances C and N sequestration in macroaggregates. This will help in sustainable ricewheat productivity in the region.

Effect of Organic Inputs on Strength and Stability of Soil Aggregates Associated Organic Carbon Concentration under Rice-Wheat Rotation in Indo-Gangetic Plain Zone of India

“…In agreement with increase in macro-aggregates by addition of rice straw and FYM in sandy loam soil in northwest India (Benbi and Senapati, 2010) and through FYM in clay soil of central India (Bandyopadhyay et al, 2010); increase in slaking-resistant macro-aggregates through manure in silt loam soil in Canada (Aoyama et al, 1999); and wheat straw in central Ohio (Blanco-Canqui and Lal, 2007). Greater amount of water stable aggregates >0.25 was also reported by Karami et al, (2012) under similar kinds of amendment (rice husk and wheat straw, cow manure) and climate (semi-arid) as in the present study.…”

Carbon and Nitrogen Dynamics and Carbon Sequestration in Soils under Different Residue Management

“…of soil C (%) x soil bulk density (g. c.c. (Benbi and Senapati, 2010) Carbon dioxide emission from rice field was measured through NaOH absorption following HCl titration method (Jain et al, 2003). Reading was taken by every 7 days interval starting from the first day of transplanting and continued to sixteenth week of transplanting.…”

Effect of Cultivation on Organic Carbon Pools and Nutrient Availability in Soil under Different Land Use System: A Review

“…The distribution of soil organic carbon (SOC) within different pools is an important consideration for understanding its dynamics and diverse role in ecosystems (Mandal et al, 2007 andBenbi et al, 2010). As an essential indicator of soil fertility, SOC and its different fractions have an important role in determining soil chemical, physical and biological properties.…”