Integrated resource management improves soil glucosidase, urease, and phosphatase activities and soil fertility during rice cultivation in Indo-Gangetic plains

Abstract

The sustainable cultivation of rice (Oryza sativa L.) without compromising yield is an emerging challenge. Field experiments were conducted at New Delhi, during 2007 and 2008 to investigate the effect of tillage, irrigation regimes, and integrated nutrient management practices on the soil enzymatic and microbial activities. The soil glucosidase (67.35%) and urease (106.75%) increased under conservation tillage compared with conventional tillage; largest increase was observed when a combination of 50% farm yard manure + 25% biofertilizer + 25% green manure (GM) was used in place of recommended dose of nitrogen (RDN) or when 25% RDN was replaced with biofertilizer or GM as nutrients in combination with conservation tillage and optimum water supply (three-irrigations) with a few exceptions. The present study has suggested that resource management practices significantly improved soil enzymatic and microbial activities under conservation tillage and optimal water supply which reduce the dependence on chemical fertilizers and make rice cultivation sustainable.

Keywords:

• conservation tillage
• optimal drainage
• integrated nutrient management (INM)
• soil enzymatic activities
• soil microbial activities
• Oryza sativa L.

Public Interest Statement

Public concerns against input intensive agriculture include excessive use of chemical fertilizers, which reportedly leach into soil and water and pollute them. The present study demonstrates that integrated use of chemical and organic fertilizers, optimum irrigation, and minimum tillage can reduce the dependence on resources besides improving soil enzyme activity and fertility. It was observed in our study that important soil enzyme activities like glucosidase, urease, alkaline, and acid phosphatase which circulate carbon, nitrogen. and phosphorous. An increase in soil microbial activity was also observed. These observations confirmed increase in soil microbial activity and fertility. To check whether it affects overall metabolic activity, soil respiration and soil microbial biomass carbon were calculated. It was observed that overall metabolic quotient of soil decreased (i.e. increase in microbial activity) when organic fertilizers were used as compared to complete chemical fertilizer treatment suggesting the improvement of soil fertility.

Additional information

Funding

This work was supported by Indian Council of Agricultural Research.

Notes on contributors

Rana P. Singh

The activity of our research group at the Division of Microbiology, Indian Agricultural research institute (New Delhi), is mainly related to the improvement of rice–wheat cropping system in Indo-Gangetic plains by integrated resource management (IRM) practice, to minimize cost of production, reduce environmental damage in developing countries, and improving food security in the developing countries. The research reported in the paper pertains to observe the effect of resource management on soil enzyme activity and hence soil fertility during rice crop cultivation. High input of resources like chemical fertilizers, tillage, and water pollutes the environment and harms soil fauna. The present research demonstrates that integrated and optimum use of resources improves soil glucosidase, urease, and phosphatase activity and overall microbial activity of soil and thus fertility of soil by mixed use of organic and chemical fertilizers and optimum use of other high input resources.