Potassium Balance under Soybean-wheat Cropping System in a 44 Year Old Long Term Fertilizer Experiment on a Vertisol

• Published in: Communications in Soil Science and Plant Analysis Vol. 53; no. 2; pp. 214 - 226
• Main Authors: Pathariya, Priyanka, Dwivedi, B.S, Dwivedi, A.K., Thakur, R.K., Singh, Muneshwar, Sarvade, S.
• Format: Journal Article
• Language: English
• Published: Philadelphia Taylor & Francis 19.01.2022; Taylor & Francis Ltd
• Subjects: Carbon; Cereal crops; Cropping systems; Depletion; Fertilizers; k uptake; K-fractions; long term fertilizer experiment; Nitrogen; Organic carbon; Organic fertilizers; organic manure; Organic wastes; Potassium; Soil; Soils; Soybeans; vertisol; Water chemistry
• ISSN: 0010-3624; 1532-2416; 1532-4133
• DOI: 10.1080/00103624.2021.1984516

Applications of fertilizers alone and in combination with organic manure significantly increased the organic carbon, available nitrogen, phosphorous, potassium, and K fractions, i.e., water soluble-K, exchangeable-K, non-exchangeable-K, lattice-K, and total-K in both surface and subsurface soils and without K input (100% NP & 100% N). Among the various K fractions, lattice K was the dominant K fraction. The highest values of these fractions were found in 100% NPK + 5 t FYM ha −1 . The relative contents of these fractions were in order, lattice-K > non-exchangeable K > exchangeable K > water soluble K, and these were higher in surface than the subsurface soils. Correlation studies revealed significant positive relationship of organic carbon and available N, P, and K with different K fractions in surface and subsurface soils. Furthermore, the minimum depletion of the K rate was recorded in 100% NPK + FYM (−2.25 kg ha −1 yr −1 ) to that of other treatments, while control showed a maximum K depletion rate (−3.86 kg ha −1 yr −1 ). Apparent K balance in soil was the lowest, −61 kg ha −1 yr −1 , in control plot followed by −165 kg ha −1 yr −1 in the treatment of 100% NPK + FYM. Hence, much attention is required for potassium fertilizers to maintain the K status of soil and to prevent K mining.