Effect of zinc nutrition on yield of rice-wheat cropping system and soil properties

A study was conducted in an ongoing experiment under AICRP on micronutrients at nursery jhilli of RPCAU, research farm. The experiment consisted of thirteen treatments, of which twelve combinations were of four doses of zinc (Zn) (2.5, 5.0, 7.5 and 10 kg ha-1), three frequencies (only once, alternate year and every year) of application along with control with the no-zinc application. Rice and wheat crops were grown in succession with the recommended dosages of fertiliser viz. 120:60:40 of N: P2O5: K2O applied as Urea, DAP, and Potash, respectively. Surface soil samples (0-15 cm) were collected after the harvest of the wheat crop in the year 2018, i.e. after completion of six years of the experiment, and analysed for soil physical and chemical properties. The availability of nitrogen, sulphur, organic carbon content and aggregate stability increased, and the bulk density, phosphorous availability decreased with increasing doses and zinc application rates. No effect on soil availability of potassium, pH and EC. The treatment T7 i.e., application of zinc @ 7.5 kg Zn ha-1 in alternate year application was the best treatment with regards to yield of rice-wheat cropping (982.9 q ha-1) and also for good physical and chemical properties of the soil.