Land Resources Research Institute, National Agricultural Research Center, Islamabad, Pakistan.
Present address:1 Soil Science Department, University of Arid Agriculture, Murree Road, Rawalpindi, Pakistan.
Greenhouse and field studies in Pakistan and elsewhere have revealed beneficial response of peanut (Arachis hypogaea L.) to sulphur (S) application. Therefore, a nutrient indexing of S in peanut crop was carried out by sampling plants and associated soils from 79 randomly selected fields in two geographical districts, Chakwal and Attock, of the rainfed Potahar plateau of Pakistan. Total S content in plants tissues and 0.15% CaCl2 extractable soil SO4-S content indicated S deficiency in 40 per cent peanut fields. Sulphur deficiency was more widespread in Attock district (−58% fields) compared with Chakwal (−36% fields), probably, because of lesser soil moisture during the crop season coupled with slightly coarser textured soils in the former district. Sulphur contents in soils and plants were strongly correlated (r = 0.85**) and so were the SO4-S contents in surface and subsoils (r = 0.91**). Sulphur availability in soils was positively related with clay (r = 0.31**), silt (r = 0.26*), and organic matter content (r = 0.33**), and negatively related with sand content (r = -0.31**). Plant S contents was also positively related with silt (r = 0.25*) and negatively with sand fraction of the soils (r = -0.27*). Soil classification at the sub-group level of USDA Soil Taxonomy System partially separated S-deficient and S-adequate peanut fields. Soil SO4-S status appears to be related to the parent material. The results of this investigation suggest the need for managing adequate S fertility in rainfed fields for harvesting optimum peanut yields.
Sulfur deficiency, peanul, Arachis hypogaea, rainfed, nutrient indexing, soil testing, plant analysis, soil properlies
