Main vegetable fertilization technology in protected area

Common characteristics of fertilizer

1. The nutrient needs a large amount of vegetables. The biological yield is high, so the amount of fertilizer per hectare is more than that of food crops. For example, the average nitrogen uptake of vegetables is 4.4 times higher than that of wheat, the phosphorus uptake is 0.2 times higher, and the potassium uptake is 1.9 times higher. The calcium absorption is 4.3 times higher and the magnesium absorption is 0.5 times higher.

The nitrogen, phosphorus and potassium contents in the stems and leaves of the nutrients and vegetables were 6.52 times, 7.08 times and 2.32 times higher than that of rice and wheat, respectively. The nitrogen, phosphorus and potassium contents of the seeds or edible organs were 2.04 of rice and wheat respectively. Times, 1.49 times and 6.91 times. Therefore, the products harvested from vegetables have more nutrients removed from the soil.

3, there are special needs for certain nutrients (1) vegetables like nitrate nitrogen; (2) large demand for potassium and calcium; (3) vegetables are sensitive to boron and molybdenum.

Protected soil characteristics

1. Soil nutrient status in protected areas

According to the survey of the soil nutrient status of some greenhouses in the greenhouses of Jinan, Tai'an, Jining, Linyi, Rizhao, Heze, Zibo, Weifang and the eight areas of Weifang, the average organic matter content in the greenhouse is 17.0 g/kg. The average average temperature is 12.5 g/kg; the average alkali leaching shed is 126.15 mg/kg, the average outside the shed is 60.11 mg/kg; the average available phosphorus shed is 196.68 mg/kg, the average outside the shed is 68.45 mg/kg; the average available potassium shed is 381.41. Mg/kg, an average of 180.44 mg/kg outside the shed. The results of the survey showed that the soil nutrients in the shed were significantly increased compared with those outside the shed, and the order was phosphorus > nitrogen > potassium > organic matter. Due to different planting years and fertilization levels and partial fertilizer application, the soil fertility status of the protected areas varies greatly, and the imbalance between the nutrients needs to be solved by balanced fertilization.

2. Soil salt and acidity accumulation in protected areas

Samples with a salt content of more than 0.3% in the shed from 0 cm to 20 cm accounted for 26.09%, 3.78 times outside the shed, the maximum value was 1.2%, and the average value was 0.27%. There was a significant salinization phenomenon. Among the salt segregants, the most accumulated soil in the shed is no3- and k+ ions compared with the outside of the shed. There is also a certain accumulation in the soil of ca2-, mg2-, cl-, and so42-sheds. The soil salt accumulation in the greenhouse is heavier and directly related to the unreasonable fertilization. The results of soil acidity test showed that the pH value of 0-20 cm was 0.46 lower than that of the soil outside the shed, and there was obvious acidification.

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