Chemical Properties of Soil Influenced by Rice-Based Cropping System under Irrigated Conditions

Abstract

Soil is one of the most vital natural resources, playing a fundamental role in agricultural productivity and long-term food security. The physico-chemical properties of soil are strongly influenced by both the nature of the parent material and the prevailing management practices, including cropping systems. Identification of suitable and sustainable cropping systems is therefore essential for maintaining soil fertility and ensuring the long-term stability of agricultural production. In this context, a field investigation was conducted at the Kuthulia Farm of Jawaharlal Nehru Krishi Vishwa Vidyalaya (JNKVV), Rewa, Madhya Pradesh, to evaluate the influence of different rice-based cropping systems on soil chemical properties. The experiment was carried out under the All India Coordinated Research Project on Farming Systems during the Kharif and Rabi seasons over four consecutive years (2008–09 to 2011–12). Ten rice-based cropping systems were evaluated, namely rice–wheat, rice–chickpea, rice–berseem (fodder + seed), rice–potato–wheat, rice–garlic, rice–toria–onion, rice–lentil, rice–green pea–wheat, rice–chickpea–linseed, and rice–mustard. The experimental soil was classified as silty clay loam with a neutral reaction (pH 7.25). The initial soil fertility status indicated a medium level of organic carbon (0.56%), low available nitrogen (224 kg ha⁻¹), low available phosphorus (8.2 kg ha⁻¹), and high available potassium (315 kg ha⁻¹). The results revealed that soil pH and electrical conductivity decreased under all rice-based cropping systems compared with the initial values, suggesting a modest improvement in soil reaction under continuous cultivation. Soil organic carbon content increased by 3.57 to 30.35% over the initial level across different cropping systems. The greatest improvement in organic carbon was observed in the rice–potato–wheat system, followed by rice–chickpea, rice–green pea–wheat, and rice–lentil sequences, indicating the beneficial effect of diversified cropping and inclusion of legumes on soil organic matter accumulation. In contrast, available nitrogen declined substantially, with reductions of approximately 60–65% compared with the initial soil status, indicating considerable nitrogen removal by crops and the need for improved nutrient management strategies. Available phosphorus increased markedly, ranging from 14.83 to 234.87% above the initial level. The highest increase in available phosphorus (234.87%) was recorded under the rice–berseem and rice–lentil systems, followed by rice–chickpea and rice–mustard, which may be attributed to improved phosphorus mobilisation and recycling under legume-based systems. Available potassium content declined by 34.39 to 51.56% compared with the initial status across the different cropping systems, reflecting substantial potassium uptake by crops over the experimental period. Overall, the study demonstrates that diversified rice-based cropping systems can influence soil chemical properties in different ways and play an important role in maintaining soil chemical health under irrigated conditions. These findings emphasise the need for balanced nutrient management and appropriate crop diversification strategies to sustain soil fertility and long-term productivity in rice-based agroecosystems.