Forms of Soil Potassium as Influenced by Long Term Application of Chemical Fertilizers and Organics in Rainfed Maize-Wheat Cropping System

Abstract

A study on potassium dynamics under long term use of variable doses of imbalanced chemical fertilizers and organics in rainfed maize-wheat system was carried out in Typic Ustipsamments of low hill zone of Himachal Pradesh between rabi (2007-08) and kharif (2008) seasons in the ongoing long-term fertilizer experiment at the research farm of CSKHPKV, HAREC, Dhaulakuan. Surface soil (0-15cm) after sixteen cropping cycles was analyzed for different forms of potassium. All the fractions of potassium viz. water soluble-K, exchangeable-K and non exchangeable-K decreased from its initial status in most of the treatments. Treatments receiving K fertilizer (100% NPK) showed increase in water soluble-K and exchangeable-K fraction over the initial status. Application of FYM (Farmyard manure) in both the seasons also increased the content of water soluble-K and exchangeable-K over the initial value. In general application of FYM with chemical fertilizers showed higher content of all the fractions compared to treatments where imbalanced inorganic fertilizers were applied (100 % N and 100 % NP). Maximum decrease in all the fractions of K was recorded in treatment 100 per cent N followed by 100 per cent NP. Use of FYM to both crops has resulted in higher yield in case of wheat crop. Water soluble-K was the important fraction of potassium contributing towards crop yields and total K uptake.

Impact of Nutrient Management Practices on Exchangeable K, Ca, Mg, CEC and Correlations with Soil Properties Under Maize-wheat Cropping System

“…This may be due to continuous cropping without addition of K for the last 62 years. Similar findings were reported by [8]. It was also observed that water soluble K of 100% NP treated plot was also significantly lower than that of 100% N treated plot.…”

“…The higher concentration of Exchangeable K under K fertilized plots in surface soil could be attributed to the addition of K through plant residues, manure and fertilizers [12] (Jadhao et al, 2018) in the plot. While the lower availability in T4 was due to continuous cropping without addition of K. Similar findings were reported by [8]. It was also observed that the concentration of exchangeable K was numerically lower in sub -surface soil as compare to surface soil in all the treatments which may be due to comparatively more weathering vegetation and supply of K from organic residues in surface layer in lower depth.…”

“…The increased status of water soluble K with Lime, FYM, P2O5, K2O treatment may also be due to stimulating effect of FYM in reducing K fixation, thereby bringing in more K into available form [9] and similar findings reported by Kumari [10]. While the lower availability in T4 was due to continuous cropping without addition of K.Similar findings were reported by [8]. On critical examination of data it was also observed that water soluble K was numerically lower in sub-surface (16-30 cm) soil than surface (0-15 cm) soil.…”

Fractions of Soil Potassium and their Depthwise Distribution under Long-Term Nutrient Management Practices in Semiarid Alfisols in India

“…Higher total potassium might be due to the supply of K through organic residues in the form of FYM coupled with minimizing the losses from leaching by retaining K+ ion on exchange sites, Kumar and Narwal, [16]. The results of study corroborate with findings of Sharma et al [8] and Sharma and Paliyal [17]. The treatments followed a similar trend as that of 0-15 cm in 15-30 cm soil layer also.…”

Potassium fractions in black soil mediated by integrated nutrient management modules under maize-chickpea cropping sequence

“…[ 23 ], Mercykutty et al . [ 26 ], Sharma and Bhandari [ 27 ], Gurumurthy and Prakasha [ 28 ], Jatav and Dewangan [ 29 ] and Sharma and Paliyal [ 30 ].…”