Soil biological properties as influenced by long term manuring and fertilization under finger millet - maize cropping system in Alfisols

Abstract

Soil degradation and poor soil health have resulted from the extensive use of mineral fertilizers to generate high agricultural yields. As an alternative to mineral fertilizers, manure application can be an effective fertilizing approach for improving soil health and biodiversity. This study aims to assess the impacts of long-term manuring and fertilization on soil biological properties in an ongoing 33-year old long-term fertilizer experiment (LTFE) under finger millet-maize cropping system in Alfisols at Gandhi Krishi Vignan Kendra, University of Agricultural Sciences, Bengaluru, during 2020. The field experiment laid in a randomized complete block design having twelve treatments with three replications. The treatments were 50% NPK (T1), 100% NPK (T2), 150% NPK (T3), 100% NPK + Hand weeding (T4), 100% NPK + Lime (T5), 100% NP (T6), 100% N (T7), 100% NPK + FYM (T8), 100% NPK (-S) (T9), 100% NPK + FYM + Lime (T10), Control (T11), Uncultivated land (T12). The microbial biomass carbon, microbial biomass nitrogen and all enzyme activities i.e. dehydrogenase, urease activity and acid phosphatase were recorded more in the uncultivated land compared cultivated land followed by treatment receiving 100% NPK + FYM + Lime and 100% NPK + FYM, however lowest activities are observed in the imbalanced fertilizer applied treatments (100% N) and control. The microbial activities are more in uncultivated land compare to cultivated land and with increase in depth of the soil, all of the soil's biological properties decreased. Imbalanced use of chemical fertilizers had the harmful effect on soil biological health. The use of inorganic fertilizers in combination with organic manure provides an alternate strategy for managing soil fertility that is both sustainable and cost-effective.