Effect of nitrate leaching of winter wheat field based on straw application in the Yellow River irrigation area of Ningxia On the nitrate-N accumulated characteristics in deep soil layer of winter wheat field in Taihang Piedmont Potential Productivity of Light and Heat Resources and Its Utilization in Winter Wheat Field Effect of swine manure application on nitrate leaching in winter wheat field in the Yellow River irrigation area of Ningxia, China. Nitrous oxide emissions from winter wheat field in the Loess Plateau