Grewal, K.S.Md.Sarware Alam2019-11-152019-11-152019http://krishikosh.egranth.ac.in/handle/1/5810135411Eight descriptive profiles representing major physiographic units of Haryana were selected and evaluated for various morphophysico-chemical properties, potassium fractions and potassium release behaviour using organic (oxalic and citric acid) and mineral acids (nitric acid). The soils varied in colour from dark brown to dark yellowish brown. The structure was predominantly sub-angular blocky in all profiles and the soil consistence varied between very sticky very plastic to non-sticky non-plastic. The soils were alkaline in reaction, non-saline, non-calcareous to slightly calcareous in nature. The exchangeable bases exhibited different regular and irregular trend as a result of variation in soil depth. the soil texture varied from sand to clay loam with low to medium OC and available P and low available N. Organic carbon and available N, P, K, Zn showed decreasing trend with increasing depth whereas Fe, Mn and Cu showed irregular trend with depth. A significant positive relationship was observed between clay and silt with CEC and organic carbon and a negative correlation with soil pH and sand. Water soluble K , exchangeable K, non-exchangeable K and total K content in soils varied from 8.70 to 24.93, 53.45 to 160.25,258.05 to 1273.10 mg kg-1 and 1.15 to 1.91% , respectively with mean values of 7.27 to 16.0, 46.46 to 130.63, 28.83 to 1392.48 mg kg-1and 1.21 to 2.03%, respectively. Water soluble potassium and exchangeable potassium was higher in surface layer which decreased with increase in depth in all the soil profiles. There was no specific trend of non-exchangeable K and total K distribution with respect to soil depth. In general, subsurface soils had higher amount of non-exchangeable-K compared to surface layers. Maximum amount of water soluble K, exchangeable K, non-exchangeable K and total K were observed in old alluvial plains (Typic Haplustepts) followed by recent alluvial plain (Typic Natrustalfs) and minimum in aeolian plains (Typic Ustipsamments). Different forms of potassium were positively and significantly correlated with organic carbon, silt and clay content and negatively correlated with sand content. The different forms of potassium were positively and significantly correlated among themselves which suggests the existence of interdependency and dynamic equilibrium between K forms. Highest amount of K was released from the soils using oxalic acid followed by nitric acid and lowest by citric acid. The highest amount of K was extracted in first five extractions and then it gradually decreased with increasing the number of extractions and finally remained almost constant thereby suggests that a major part of potassium from the reserve pool had been released in the initial five extractions.The maximum release of non-exchangeable K was recorded in old alluvial plains (Typic Haplustepts) followed by recent alluvial plains (Typic Natrustalfs), recent alluvial plains (Typic Ustorthent),Siwallik hills valley (Typic Udorthents), Siwallik foot hills (Typic Ustorthents), Piedmont plain (Typic Ustochrepts), aeolian plain (Typic Ustorthents) and minimum aeolian plain (Typic Ustipsamments) by all the three acids. Total extractable-K, total step-K constant rate-K and CPK value varied among different profile soils. The cumulative release of non-exchangeable K by repeated extraction followed a semi-logarithmic behaviour with number of extractions, indicating that the release of non-exchangeable K decreased with sequential extractions. The dry matter yield of maize increased with application of potassium. The increase in dry matter yield was significant in soils having medium amounts of ammonium acetate extractable potassium and non-significant in soils where level of potassium was adequate. Potassium concentration in dry matter of maize increased with application of increasing levels of K in all soils. The increase in N,P, K and Zn uptake by maize plants was significant in majority of soils at 60 mg kg-1(except old alluvial plain (Typic Haplustepts) and recent alluvial plain (Typic Natrustalfs) where 90 mg kg-1 K level was statistically at par with 60 mg kg-1. It was further observed that available as well as non-exchangeable K increased in all soils after maize harvest whereas it decreased in controls pots. The magnitude of increase was higher at higher levels of K application. Dry matter yield and K uptake were positively and significantly correlated with different forms of potassium.enThesis