Effect of Organic and Modern Method of Cotton Cultivation on Soil Nutrient Status

The main objective of the study was to assess the soil nutrient status of two cotton (Gossypium hirsutum L.) cultivation systems (organic and modern method of cultivation) established in 1994. In general, the data indicate a depletion of the nutrient status with depth (0–0.1, 0.1–0.2, 0.2–0.3, 0.3–0.6, and 0.6–0.9 m). There was a significant build up of organic carbon (C) and nutrients, except iron (Fe) and magnesium (Mg), in the organic cultivation system (OCS) compared to the modern method of cultivation (MMC). Most of the accumulation was noticed in the top 0–0.3 m. The concentration of the mobile nutrient was significantly greater in the surface as well as in the deeper layers of the OCS plots than the MMC plots. Extractable P was 3.8-fold greater in the OCS than MMC plot in the top 0.1 m soil layer. At 0.3–0.6 m soil depth, it was 3-fold greater. Other immobile nutrients such as zinc (Zn), Fe, manganese (Mn), and copper (Cu) were also significantly greater in the 0.3–0.6 m depth in the OCS plots compared to the MMC plots possibly due to movement of enriched topsoil through the cracks following cultivations.