Effect of long-term manuring and fertilization on depth wise distribution of potassium fractions under sorghum-wheat cropping sequence in vertisol Jadhao S.D.*, Arjun Dipali, Mali D.V., Singh Muneshwar1, Kharche V.K., Wanjari R.H.1, Kadu P.R., Sonune B.A., Magare P.N. Department of Soil Science and Agricultural Chemistry, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, 444 104, Maharashtra 1Indian Institute of Soil Science, Bhopal, Madhya Pradesh *Corresponding author Email: sdjadhao@rediffmail.com
Online published on 28 January, 2019. Abstract The effect of long-term manuring and fertilization on depth-wise distribution of potassium (K) fractions under sorghum-wheat cropping sequence in Vertisols was studied under the long-term fertilizer experiment (AICRP's) at Akola, Maharashtra. The treatments comprised of 50% NPK, 100% NPK (P applied through SSP), 150% NPK, 100% NPK(−S), 100% NPK + Zn @ 2.5 kg ha−1, 100% NP, 100% N, 100% NPK + FYM @ 5 t ha−1, 100% NPKS, FYM @ 10 t ha−1 to sorghum and wheat, 75% NPK + 25% N through FYM and Control laid out in randomized block design. The results of the present study revealed that, application of 100% NPK + FYM @ 5 t ha−1 significantly increased the fractions of K viz., available K (210 mg kg−1), water soluble K (8.75 mg kg−1), exchangeable K (201 mg kg−1), non-exchangeable K (945 mg kg−1) and lattice K (17078 mg kg−1) in 0–15 cm depth. Similar trends in K fractions were also noted in 15–30 and 3045 cm depths. The sequential order of dominance of different fractions of K were: lattice K > nonexchangeable K > exchangeable K > available K > water soluble K. The highest negative balance of K was recorded with the application of 100% NP (−3513 kg ha−1) followed by 100% NPK + FYM @ 5 t ha−1 (−3110 kg ha−1) and 150% NPK (−2838 kg ha−1). The application of NPK + FYM (470 kg ha−1), 150% NPK (432 kg ha−1) and 100% NPK (378 kg ha−1) resulted in improving the status of available K over its initial (358 kg ha−1) status. The grain yield of sorghum and wheat was influenced significantly with the application of NPK + FYM (5.27 and 3.39 t ha−1) followed by 150% NPK (4.87 and 3.21 t ha−1). The SYI of the system was improved with NPK + FYM as compared to control for sorghum (−0.008) and wheat (0.004). The contribution of non-exchangeable K to total uptake was higher in NP (3316 kg ha−1) followed by NPK + FYM (3060 kg ha−1). All the K forms showed significant and positive correlation with yield and uptake of K. There exists a significant and positive correlation indicating dynamic equilibrium among all forms of K. Top Keywords Potassium fractions, sorghum-wheat sequence, FYM, SYI, grain yield. Top |