Long term effect of different crop rotations on soil health and different carbon pools in a mollisol

Abstract

Field experiments were conducted during the year 2020-21 and 2021-22 in E2 block of newlineNorman E. Borlogue Crop Research Center of GovindBallabh Pant University of Agriculture newlineand Technology, Pantnagar, Uttarakhand on the long term effect of different crop rotations on newlinesoil health and different carbon pools in a Mollisol. The objective was to study the effect of newlinedifferent approaches to crop rotations on soil health and to investigate the impact of different newlinecrop rotations on soil health. The experiment was laid out in randomized block designs with newlinethree replications and eleven treatments i.e. T1 (Rice - Wheat - fallow), T2 (Rice - Veg. pea - newlinesummer rice), T3 (Maize - Wheat - Cowpea), T4 (Rice - Wheat - Sesbania), T5 (Maize - Toria - newlineUrd), T6 (Rice - Yellow Sarson - Grain Cowpea), T7 (Multi Cut Sorghum - Barseem + Oat - newlineMaize + Cowpea), T8 (H. Napier + Fodder cowpea - Barseem - Fodder cowpea), T9 (Basmati newlinerice - Potato - Maize Cob), T10 (Maize - Broccoli -Okra) and T11 (fallow). Green manure newline(Sesbania) was used in crop rotation, cut and incorporated intothe soil each year during the newlinekharifseason only and its residual effect on the crop was seen. The inclusion of legume crops newlinewas done between the different crop rotations. After the harvest of crops, the data for grain and newlinefodder yield was recorded for respective plots. The soil samples (0-20cm) were collected in newlineJune 2021 and June 2022 for the fourth and fifth-year crop rotation study respectively. newlineThe experiment results revealed that better soil health and carbon pools of soil were newlineobserved with the sesbania and legume-based crop rotations during the fourth (2020) and fifth newline(2021)year crop rotations as compared to the cereals crop rotations and fallow land. Per cent newlineachievement of physical chemical and biological properties were also recorded relatively higher newlineunder green manure and legume-based crop rotations during the fourth (2020) and fifth (2021) newlineyear crop rotations as compared to the fallow land. The incorporation of sesbania and legume newlinecrops in crop rotation did not have any remarkable influence on soil texture, particle density, pH newlineand EC. Soil physical(Bulk density, water holding capacity and porosity) chemical properties newline(OC, NPK, Ca2+ Mg2+ Sulfur and zinc) and biological properties (Microbial counts, microbial newlinebiomass carbon and enzymatic activity), carbon status (Total organic carbon,organic carbon newlinestorage, KMnO4oxidizable carbon and organic matter), carbon pools (active and passive) and newlinesoil health indices (Structure stability index, soil health index, biochemical index and carbon newlinemanagement index) improved under the sesbania and legume-based crop rotations as compared newlineto the uncultivated land in fourth(2020) and fifth(2021) year crop rotations.A correlation and newlinescoring technique was adopted to identify the relationship between different soil properties and newlinesoil health determination respectively. The high category soil health index was identified with newlinelegume and sesbania-based crop rotations under fourth(2020) and fifth(2021) year crop newlinerotations. Thus, the present study provides a strong basis for the recommendation of sesbania newlineand legume-based crop rotation which helps conserve soil health, soil fertilityand environmental newlinequality. newline