Attention should be paid to the application of base fertilizer for vegetables in greenhouse

Greenhouse vegetables have high multiple cropping index, high yield and large fertilizer requirement, while the bottom fertilizer has a great influence on the yield, quality and soil properties of vegetables, which is the most basic link in fertilization and is very important to the growth and development of vegetables. Therefore, the base fertilizer must be applied reasonably, and the following problems should be paid attention to when applying the base fertilizer:

1. To determine the amount of fertilizer applied in the greenhouse according to the target yield of vegetables, we must consider the level of soil fertility and the amount of fertilizer required by vegetables. In general, 30% of the total amount of nitrogen fertilizer, 80% of the total amount of phosphate fertilizer, 50% of the total amount of potash fertilizer as base fertilizer, biological fertilizer and micro-fertilizer as far as possible. For example, the yield of autumn tomato is about 8000kg to 9000kg. For every 1000 kg tomato produced in this range, it needs to absorb 4.4kg of nitrogen, 1.1kg of phosphorus pentoxide, 4.8kg of potassium oxide, and the ratio of nitrogen, phosphorus and potassium is 1 ∶ 0.25kg ∶ 1.1, and more calcium and boron are needed. Among them, high phosphorus type fertilizer should be selected for base fertilizer and low phosphorus type fertilizer should be selected for topdressing. The suitable amount of base fertilizer is 40-50 kg, the proportion of nitrogen, phosphorus and potassium is 1 ∶ 1 ∶ 0.75, the amount of topdressing is 75-85 kg, and the ratio of nitrogen, phosphorus and potassium is 1 ∶ 0.2 ∶ 0.85. Second, ensure that the amount of organic fertilizer is adequate

Organic fertilizer (including farm manure, barnyard manure and cake manure) is the most suitable to be used as base fertilizer, and more bio-organic fertilizer should be applied to the aged greenhouse with high soil fertility. In order to keep the soil fertility and organic matter in the greenhouse not decreased or slightly increased, it is necessary to supplement organic fertilizer to the greenhouse soil. According to the change law of soil organic matter in greenhouse and the principle of the highest yield when the ratio of organic nitrogen to inorganic nitrogen is 1 ∶ 0.4: 1, in order to keep the soil organic matter in greenhouse above 2% to ensure higher yield, organic fertilizer with 30% organic matter content should be applied not less than 2000 kg / mu every year.

3. Determine the application method of base fertilizer according to the weather and growth characteristics.

From the way of fertilization, the general base fertilizer should be applied to the whole plough layer, that is, the depth of 15cm to 30cm. For organic fertilizer, nitrogen fertilizer, potassium fertilizer and so on, they can be mixed and spread evenly on the surface, and then ploughed into the soil to achieve a uniform mixture of fertilizer and soil in the whole plough layer, so as to facilitate the absorption and utilization of nutrients in different root layers of vegetables. Due to poor mobility, phosphate fertilizer should be concentrated under ridges (or ridges), so that phosphate fertilizer can be evenly distributed in the dense layer of roots.

Biological fertilizer stimulates the growth of vegetables with the activities or metabolites of live bacteria. If mixed with fungicides, it is easy to kill live bacteria and reduce the effect. For example, at present, many bacterial fertilizers are mainly actinomycetes, which should be used alone, especially not mixed with bactericides (DT, streptomycin, etc.). In addition, the environmental conditions which are not conducive to the survival of beneficial bacteria such as too dry soil, too strong light, too high salinity and so on should be avoided.

Li Chunzhen, Agricultural Bureau of Gucheng County