Use of Gypsum to Increase Fertilizer Efficiency on Normal Soils

摘要

Field experiments were conducted on maize and wheat under normal soil conditions at Qalla, Charsadda and Tarnab, Peshawar irrigated with canal water to evaluate the effect of gypsum application on the efficiency of NPK fertilizers. Gypsum was applied @ 0, 500 and 1000 kg ha^-1 with two levels of fertilizers i.e. recommended dose of NPK (120,90, 60 kg ha^-1) and half dose (60, 45 and 30 kg ha^-1) respectively. Maximum grain (3605 kg ha^-1) and stalk (9922 kg ha^-1) yield of maize was recorded at Qalla by the application of recommended dose of NPK with 1000 kg gypsum ha^-1. The NPK with 500 kg gypsum ha^-1 ranked second in this respect. Half dose of the NPK without any gypsum gave minimum grain (2248 kg ha^-1) and stalk (3435 kg ha^-1) yield. The yields were non- significantly different at Tarnab under the same treatment compared with that of Qalla. During the second year, the soil conditions improved and yield of grain (2883 kg ha^-1) as well as stalk (15833 kg ha^-1) was better at both sites. Wheat yield was non-significantly different at Tarnab. Uptake of different ions was variable. Uptake of P, K, Zn and Cu decreased while that of Mn and Fe increased during the second year. Maximum yield of maize grain (2883 kg ha^-1) and stalk (15833 kg ha^-1) with half dose and wheat grain (3605 kg ha^-1) and stalk (12910 kg ha^-1) was obtained by application of 1000 kg ha^-1 gypsum with full dose of NPK.