Effect of zinc sulphate application and the cyclic incorporation of cereal straw on yields, the tissue concentration and uptake of Zn by crops and availability of Zn in soil under rice–wheat rotation

Background Soil incorporation of cereal straw to avoidburning and air pollutionmay influence the availability of Zn,a criticalmicronutrient in cereal production. Field experimentwas carried out to evaluate the effect of zinc sulphate applicationand the cyclic incorporation of cereal straw on theyields, tissue concentration and uptake of Zn by rice andwheat crops and availability of Zn in soil.Results Application of 25 kgZnSO4 ha-1 to I year rice cropincreased the grain yields of rice by 24.3 and 56.3 % overcontrol during I and II year, respectively.Application of 25 kgZnSO4 ha-1 to I year rice crop ? cyclic incorporation of 1.5 tstraw ha-1 increased the grain yields of rice by 21.4 and87.4 % over control during I and II year, respectively. In Iyear, the grain yield of wheat crop was not significantlyinfluenced by the different treatments while in II year thehighest wheat grain yield was recorded with 25 kg ZnSO4ha-1 to I year rice crop ? cyclic incorporation of 6.0 t cerealstraw ha-1. Application of 25 kg ZnSO4 ha-1 to I yearrice ? cyclic incorporation of 1.5 t straw ha-1 resulted in asignificant increase in the concentration of Zn in the planttissues of both rice and wheat crops. The cyclic incorporationof 1.5–3.0 t cereal strawha-1 maintained better availability ofZnSO4 applied to I year rice crop to the subsequently growncrops.Conclusion Soil application of 25 kg ZnSO4 along withincorporation of 1.5 t cereal straw ha-1 prior to I year ricetransplanting followed by cyclic incorporation of cerealstraw in subsequent crops ensures higher availability of Znin soil and higher yields in rice–wheat rotation.