Effects of Different Rates of N and K on the Nutrient Uptakeand Partition of Cabbage
The field trial was conducted for studying the effects of different rates of N and K on the nutrient uptake and partition of cabbage (Brassica oleracea var.capitata L.).The results revealed that sole application of nitrogen could increase the contents of N, B, Mn, Zn and decrease the contents of K,Ca, Mg,Cu and Fe.The sole potassium fertilizer could increase the K and contents of all microelements in cabbage heads, but decease the contents of other nutrients such as N, Ca and Mg. The combination of N,K fertilizer could alleviate the negative impacts of N fertilizer on K content, and K fertilizer on Mg content. The effect of combined N and K on the microelement contents would depend upon the response of sole application of N and K, and their interactions. Nitrogen and potassium fertilizer enhanced the nutrient uptakes,and the translocation of Ca and Mg from side leaves to heads. Application of N and K obviously increased the proportion of nutrients in the cabbage heads, and decreases the proportion in side leaves, which had positive influences on the growth, yield, quality and nutritional values of cabbage heads.