Nutrient effect analysis of nitrogen and phosphorus in crop production in cold and arid region of North China under rotation cropping

To determine the nitrogen and phosphorus use efficiency of main crops in the cold and arid region of North China is the theoretical basis for innovating crop configuration technologies by exploiting the advantages of crop ecological adaptations and nutrient use efficiency to achieve the full utilization of regional natural and social resources. In the sandy chestnut soil farmland of Zhangbei County, Hebei Province, a rotation experiment with five crops, including potatoes, flax, millet, oat and sugar beets, was conducted in sandy chestnut soil by crossing plots design, to study the nutrient utilization effect of main crop in cold and arid region of North China. The results showed that the difference of biomass among five crops was 1.17-2.34 times, the highest was 10 290 kg·hm^-2 in beets, followed by oat, the lowest was 4 393 kg·hm^-2 in flax, and the yield difference among crops was significant. The differences in uptake of total nitrogen and total phosphorus in crops was 1.03-2.10 and 1.00-1.92 times respectively, the highest uptake of total nitrogen was 199 kg·hm^-2 in beets, and the maximum uptake of total phosphorus was 29 kg·hm^-2 in oat, and the lowest uptake of total nitrogen and total phosphorus was 95 kg·hm^-2 and 15 kg·hm^-2 in flax, respectively. The use efficiency of nitrogen and phosphorus was 43.82-53.11 kg·kg^-1 and 287.60-574.88 kg·kg^-1, among which beet had the highest use efficiency of nitrogen and phosphorus nutrients. N, P input and output ratios of five crops changed between 0.50-1.65 and 0.34-1.83, the ratios of oat were the highest. In cold arid region of North China, the crop type is the main factor that causes difference of crop yield, nitrogen and phosphorus uptake and use efficiency, the effect of previous crop on soil characters was not obvious. Beet is a crop that can achieve high yield and N, P use efficiency, oat is a crop that can efficiently use nitrogen and phosphorus from soil. Potato followed by beet, and beet followed by oat were more possible to improve yield.