First, the law of kidney bean fertilizer requirement
The nutrient requirements of kidney beans will vary greatly due to different varieties. Usually, vine varieties need more nutrients than dwarf varieties.
According to data research, every 1000 kg kidney bean needs 3.4 kg pure nitrogen, 2.3 kg phosphorus pentoxide and 5.9 kg potassium oxide.
One thing is the same, that is, the nutrient absorption process and trend of dwarf varieties and creeping varieties are roughly the same, while the absorption of nitrogen, potassium and calcium is relatively large and fast, while the absorption of phosphorus is very slow and the absorption is relatively small, and the period of maximum nutrient absorption is from flowering to seed expansion and maturity.
Although kidney bean root system has nodules, its nitrogen fixation ability is relatively low, and the demand for nitrogen fertilizer is still relatively large. Nitrogen application in early stage can reduce flowering and increase pod number. Compared with ammonium nitrogen, nitrate nitrogen is beneficial to the growth and development of kidney beans. When ammonium nitrogen increased, the number of pods and the weight of individual kidney beans decreased.
Phosphate fertilizer and potash fertilizer for kidney beans, phosphate fertilizer and potash fertilizer play a very important role in the growth and nodule formation of kidney beans. Therefore, sufficient phosphorus supply is needed in the early stage of kidney bean growth and development, and timely application of potassium fertilizer in the middle and late stage can not only promote pod expansion, but also delay root senescence.
Kidney beans are prone to magnesium deficiency. When magnesium in the soil is insufficient, it first appears on the primary leaves after sowing 1 month, then turns yellow and becomes weak between the veins of the first real leaf, and then gradually develops from the lower leaves to the upper leaves, lasting for about 7 days, and then begins to decline, and the growth of kidney beans will also be obviously weakened, resulting in a decline in yield. In this soil,
The growth period of kidney bean can be divided into germination stage, seedling stage, vine pulling stage and flowering and pod setting stage. Kidney beans absorb more nitrogen and potassium while growing, but less phosphorus. However, if phosphorus is lacking, the growth of kidney bean plants and their rhizobia will be poor, which will also lead to less flowering and pods, and few seeds in pods, which will lead to a decline in yield.
Kidney beans like nitrate nitrogen fertilizer. If there is too much ammonium nitrogen fertilizer, their roots will turn black. If rhizobia are reduced, the leaves of green beans will not only be uneven, but also fade. Kidney beans prefer potassium fertilizer, especially the amount of potassium fertilizer absorbed by kidney beans will increase sharply during flowering and pod setting, so we must pay attention to potassium supplementation at this stage. The activity of bean rhizobia is also related to some trace elements such as molybdenum and boron. If these elements are lacking, it will affect the normal metabolism of plants.
Second, the correct fertilization method of kidney beans
After understanding the law of kidney bean fertilizer requirement, the fertilization plan can be made clear.
1, application of base fertilizer
Bean is a fattening crop in leguminous vegetables. Although there are nodules, the nitrogen fixation function is very weak. Note that it is suggested to use the available nutrients in the base fertilizer to promote the growth and development of plants at the seedling stage when the nodules are undeveloped. It is suggested to apply 4000 ~ 5000 kg of stable fertilizer per mu, or 5000 kg of decomposed garbage fertilizer, 20 ~ 35 kg of calcium superphosphate and 6500 kg of plant ash. If it is a dwarf variety, the amount of base fertilizer can be reduced appropriately.
The roots of kidney beans need high oxygen in the soil. If chicken manure or other organic fertilizers are applied, the reducing gas in the soil will increase, so the oxygen will decrease, leading to premature aging of rotten seeds and kidney bean roots, which will definitely affect the yield. Therefore, when applying base fertilizer, we must pay attention to choosing completely decomposed organic fertilizer, and at the same time, we should pay attention not to use too much nitrogen fertilizer as seed fertilizer.
2. Top dressing management of kidney beans
20 ~ 25 days after sowing, when the flower buds begin to differentiate, if the base fertilizer is not applied enough, the kidney beans should be topdressing in time when there are symptoms of fertilizer deficiency. It is suggested that 20% ~ 30% biogas slurry should be topdressing per mu, which is about 1500 kg, or 4 ~ 4 potassium sulfate can be added per 1000 kg of thin manure. The effect of topdressing kidney beans as soon as possible is obvious, but one thing is that applying too much nitrogen fertilizer at seedling stage will be counterproductive and make kidney beans grow white, so whether topdressing is needed must be decided according to the growth of plants.
The above is the law of kidney bean fertilizer demand and kidney bean fertilization management, hoping to help your kidney bean planting.