In view of the excessive fertilization in tomato production, the amount of nitrogen, phosphorus and potassium fertilizers is too high, the ratio of nutrient input is unreasonable, the accumulation of soil nitrogen, phosphorus and potassium nutrients is obvious, excessive irrigation leads to serious nutrient loss, and soil acidification is common. Ca,Mg, B and other elements supply obstacles, continuous cropping obstacles, etc. lead to serious degradation of soil quality, nutrient absorption efficiency decline and vegetable quality decline. The following principles of tomato fertilization are proposed:
(1) Reasonable application of organic fertilizer, adjustment of nitrogen, phosphorus, potassium fertilizer dosage, non-calcareous soil and acidic soil need to supplement calcium, magnesium, boron and other medium and trace elements.
(2) Reasonable distribution of chemical fertilizers according to tomato crop yield, stubble and soil fertility conditions. In early spring, it is not advisable to apply frequent topdressing in the early stage of growth, and pay attention to topdressing after flowering and in the middle and late stages.
(3) Combined with high-yield cultivation techniques, it is recommended to irrigate the roots of tomato at the seedling stage, and the principle of "small amount and many times" is adopted to rationally irrigate and fertilize.
(4) For old sheds with degraded soil, straws should be returned to the field or organic fertilizers with high C/N ratio should be applied, poultry manure should be reduced, and the number of crop rotations should be increased to achieve the purpose of removing salt and reducing obstacles to continuous cropping.
(5) When the tomato planting soil is seriously acidified, an appropriate amount of acid soil conditioner such as lime should be applied.
(1) Tomato seedling fertilizer should be increased with decomposed organic fertilizer and supplemented with phosphorus fertilizer. Apply 60-100 kg of decomposed poultry manure per 10 square meters of seedbed, 0.5-1 kg of calcium, magnesium and phosphate fertilizers, and 0.5 kg of potassium sulfate. According to the situation of tomato seedlings, spray 0.05%~0.1% urea solution 1~2 times.
(2) Apply high-quality organic fertilizer 30~45 cubic meters per hectare as base fertilizer.
(3) The tomato yield level is 270000~150000 kg/ha: nitrogen fertilizer (N) 450~600 kg/ha, phosphate fertilizer (P2O5) 225~300 kg/ha, potash fertilizer (K2O) 600~750 kg/ha.
(4) The tomato yield level is 90000~120000 kg/ha: nitrogen fertilizer (N) 300~450 kg/ha, phosphate fertilizer (P2O5) 150~225 kg/ha, potash fertilizer (K2O) 450~525 kg/ha.
(5) Tomato yield level 60000~90000 kg/ha: nitrogen fertilizer (N) 225~300 kg/ha, phosphate fertilizer (P2O5) 120~150 kg/ha, potash fertilizer (K2O) 300~375 kg/ha.
Calcium, magnesium and boron deficiency are prone to occur when tomato soil pH is less than 6. Lime (calcium fertilizer) 700-1125 kg/ha, magnesium sulfate (magnesium fertilizer) 60-90 kg/ha, and extra-root supplementary application 2-3 times 0.1% boron fertilizer.
More than 70% of the phosphorus fertilizer is applied as the base fertilizer strip (hole), the rest is topdressed with compound fertilizer, 20%~30% of nitrogen and potassium fertilizer is applied as the base, and 70%~80% is topdressed with water 3~10 times during the period from flowering to ear enlargement. The nitrogen fertilizer (N) should not exceed 75 kg/ha each time.