Effect of Integrated Nutrient Management Practices on Soil Quality Indicators and Plant Growth in Greengram on Alfisol

Abstract

A field experiment was conducted at farmer fields at Vagarai, Dindigul District (Tamil Nadu) during the summer season of 2023 with green gram as a test crop. The main objectives of the present study focus on studying the impact of Integrated Nutrient Management (INM) practices on soil quality indicators and the growth of green gram (Vigna radiata). Alfisols are a specific soil order found in various parts of the world, known for their natural fertility and suitability for agriculture. However, continuous cultivation and improper nutrient management can lead to soil degradation, nutrient depletion, and reduced crop productivity. To address these challenges, researchers are exploring the potential of INM practices, which involve the balanced use of organic and inorganic fertilizers, to improve soil health and optimize crop growth. The study aims to assess how various INM treatments impact soil quality indicators. These indicators may include soil organic matter content, nutrient levels (e.g., nitrogen, phosphorus, potassium), pH, and analyze how the different INM practices influence the growth and performance of greengram crops. Organic manures viz. Farm Yard Manure (FYM) and vermicompost on different combinations were evaluated in a Randomized Block Design with three replications viz. T1-Absolute control, T2 -Vermicompost alone @5 t ha-1, T3 -FYM alone @ 12.5 t ha-1, T4 -STCR - NPK alone -0.8 t/ha, T5 -STCR -NPK alone -1 t/ha, T 6 -STCR -NPK alone -1.2 t/ha, T7 -STCR -IPNS -0.8 t/ha, T8 -STCR -IPNS -1 t/ha, T9 -STCR -IPNS -1.2 t/ha, T10 -Blanket (100 % RDF), T11 -Blanket (25:50:25) + FYM@ 12.5t ha-1 and T12-Farmer’s practice. Evaluating the physical, chemical, and biological indicators, the integrated module of organic and inorganic fertilization reflected a significant improvement in soil characteristics such as the available nitrogen, phosphorus, potassium, and soil biological characteristics encircling bacterial, fungal and actinomycetes count. The STCR -IPNS - 1.2 t ha-1 (T9) proved to be the best treatment in terms of SPAD chlorophyll meter reading, the maximum number of nodules (21.24, 30.49, 24.49 at 30, 45, and 60 DAS respectively), the highest grain yield (1225kg ha-1), and nutrient (N, P, K) availability. The population of Bacteria, fungi, and Actinomycetes (27.5, 9.8, and 27.1 soil respectively), was also significantly higher in STCR -IPNS - 1.2 t ha-1(T9). Thus, the combined application of manures and fertilizers can be recommended as a nutrient management strategy for yield enhancement and soil quality maintenance of green gram cultivation in soils of the southern Tamil Nadu region.