Guiding opinions on winter wheat scientific fertilization in North China Plain

1. Fertilization problems and fertilization principles

In view of the excessive application of nitrogen fertilizer in winter wheat in North China Plain, the proportion of nitrogen, phosphorus and potassium nutrients is not balanced, the fertilizer utilization rate is low, the area of ​​one-time fertilization is large, the supply of nitrogen fertilizer is insufficient in the later stage, and the deficiency of trace elements such as sulfur, zinc and boron Occurrence, shallow soil ploughing, poor water retention and fertilizer retention, and the following fertilization principles:

(1) According to the soil fertilization results, the amount of nitrogen fertilizer is appropriately adjusted;

(2) Nitrogen fertilizer should be applied in different stages, and the proportion of application in the middle and late growth stages should be appropriately increased;

(3) Efficient application of phosphorus and potassium fertilizers according to soil fertility conditions;

(4) Adding organic fertilizer, promoting organic and inorganic cooperation, increasing the intensity of straw returning, and improving soil water retention and fertilizer retention capacity;

(5) Pay attention to the application of trace elements in sulfur, zinc and boron;

(6) Fertilizer application combined with high-yield and high-quality cultivation techniques.

2. Fertilization amount and method

(1) The production level is above 600 kg/mu: nitrogen fertilizer (N) 16~18 kg/mu, phosphate fertilizer (P2O5) 8~10 kg/mu, potash fertilizer (K2O) 5~8 kg/mu.

(2) The production level is 500~600 kg/mu: nitrogen fertilizer (N) 14~16 kg/mu, phosphate fertilizer (P2O5) 7~9 kg/mu, potash fertilizer (K2O) 4~6 kg/mu.

(3) The production level is 400~500 kg/mu: nitrogen fertilizer (N) 12~14 kg/mu, phosphate fertilizer (P2O5) 6~8 kg/mu, potash fertilizer (K2O) 3~5 kg/mu.

(4) The production level is 300~400 kg/mu: nitrogen fertilizer (N) 10~12 kg/mu, phosphate fertilizer (P2O5) 4~6 kg/mu, potash fertilizer (K2O) 1~4 kg/mu.

(5) The production level is below 300 kg/mu: nitrogen fertilizer (N) 8~10 kg/mu, phosphate fertilizer (P2O5) 3~5 kg/mu, potassium fertilizer (K2O) 0~3 kg/mu.

In the sulfur-deficient area, sulfur can be applied at a rate of 2 kg/mu. If other sulfur-containing fertilizers are used, the amount of sulfur can be reduced. In the zinc-deficient or manganese-deficient areas, zinc sulfate or manganese sulfate can be applied at 1~2 kg/mu. The boron area may be applied with borax 0.5~1 kg/mu as appropriate. It is recommended to combine the “one spray three prevention” to spray the trace element foliar fertilizer in the grain filling stage of wheat or to spray the surface with 50-50 kg of potassium dihydrogen phosphate plus 0.5~1 kg of urea to 50 kg of water.

When the yield level is below 400 kg/mu, the proportion of nitrogen fertilizer as base fertilizer and top dressing can be half. When the yield per unit level exceeds 500 kg/mu, 1/3 of the total amount of nitrogen fertilizer is applied as base fertilizer, and 2/3 is applied as topdressing at jointing stage, heading stage and filling stage. Phosphorus and potassium fertilizers and medium and trace element fertilizers are all applied as base fertilizers.

If the base fertilizer is applied with organic fertilizer, the amount of chemical fertilizer can be reduced as appropriate.

(Nanyu)