| Potassium（K）is one of the three major essential nutrients for crops.Soil K consumption has become more obvious especially in dryland of the Loess Plateau,due to insufficient investment in the rapid agriculture development.Zinc（Zn）plays an important role in human health,and Zn deficiency has become a global problem.About a third of the world’s population and 100 million people in China are suffering from Zn malnutrition.Wheat is one of the main food crops in China,and also the major food crop in the Loess Plateau.During 2017 to 2018,a field experiment was carried out in dryland of the Loess Plateau,with 5 levels for K(0,60,120,180,240 kg K2O ha-1)and Zn(0,6.8,13.6,20.5,27.3 kg Zn ha-1)respectively,to investigate effects of soil K and Zn application on wheat yield,biomass,yield composition,K and Zn absorption and utilization,grain nutrient content,and available soil K,Zn and other nutrients.Obtained results are follows:1.Application of K and Zn to soil did not significantly affect the yield,biomass,harvest index and yield components of winter wheat.However,with the increase of K application rates,the ear and grain numbers,and the yield and biomass of winter wheat tended to increase.2.Dry matter accumulation before flowering,dry matter translocation after flowering,the translocation efficiency and the contribution rate to yield formation were also not significantly affected by the K and Zn application.However,the dry matter translocation after flowering,translocation efficiency and contribution rate were changed consistently,and obtained the lowest when K and Zn were applied at 120 kg ha-11 and 60 kg ha-1,respectively.3.Potassium accumulation before flowering and its translocation after flowering were significantly increased by 13%and 8%with K application,compared with that with no K application.However,application of K and Zn fertilizers showed no significant effects on soil nitrogen（N）,phosphorus（P）,K,calcium（Ca）,magnesium（Mg）and sulfur（S）contents.4.Zinc application significantly increased the Zn content of wheat grains.The average grain Zn content was 21.8 mg kg-11 with Zn fertilizer applied,which was 26.9%higher than that with no Zn application.Different from Zn content,grain Mn content was significantly decreased by Zn application.Appropriate amount of K apalication was found to be able to increase the grain Mn content.5.Soil Zn application significantly increased the available soil Zn,and it reached 3.45mg kg-11 at harvest,with 170%of increase compared with no Zn application.Soil K application did not significantly increase the available soil K,but significantly increased the available soil S,being 55%and 54%higher in 20-40 cm soil at flowering and harvest,respectively.In conclusion,in the one-year field experiment in dryland of the Loess Plateau,application of K and Zn fertilizers did not significantly affect the growth and yield of winter wheat,but the application of K fertilizer promoted the K accumulation before flowering and its translocation after flowering,and Zn application significantly improved the capacity of soil Zn supply,and increased the Zn content of wheat grains. |
