1.Improper fertilizers to vegetables
①.Excessive use of chemical fertilizers is the main problems existing in vegetable Fertilization, especially in inorganic nitrogen is most serious. Due to the lack of other nutrients, causes the quality descend vegetables, As vulnerable to rot caused by food storage, taste becomes poor. These can be perceived by attention to characters, but the excessive accumulation of nitrate and its potential harmfulness is easy. Excessive use of nitrogen content of notrite in environment and crops, easy absorption and enrichment of nitrate in vegetables intake of nitrate, human body is 70% from vegetables. Although no toxic, but nitrate itself is consumed by reduction of nitrite and nitrite and amine generation of ammonium nitrate is one of the compounds, strong carcinogenicity induced time with increasing intake and cancer. Excessive nitrogen applied with soil, water, improve the downward leaching of nitrate content in water, causing ecological environment deterioration.
②.potassium fertilizer seems too low
Vegetables are potassium crops, if the absorption of nitrogen and potassium is 100% absorption, average for 105% – 250% for 150% – 160 percent, higher than the crops. Vegetable crops grow from early to late need k k deficiency, regardless of which stage, even cut will lead to negative consequences. Fruit class later k, will result in production.
2.Vegetables improvement measures
①.Control and improvement of nitrogen fertilizer application surueyed
The reasonable nitrogen fertilizer besides can improve the yield of vegetables, quality of vegetables have a reasonable, therefore the improvement of vegetables production is one of the major problems. In nitrogen, which should be paid attention to in deep soil, cover, and the air is separated, reduce volatilization, ammonium n can be reduced, the loss of soil adsorption. Deep ground broadcasting, can increase more than 10-30%, chemical fertilizer utilization ratio of effective ingredients can reach 50-60. Using the deep furrow, seeds, according to the ditch, or hole can be applied into full play.
②.potassium fertilizer increased
Increasing potassium fertilizer can increase vegetable yield on the other hand, make vegetables nitrate reducing, improve the quality of vegetables. Vegetable crops and vegetables, or potassium nitrate of absorption. NO3 – is anion, crop root absorb anion must large k uptake of cation in order to achieve that, most of the ions balance inside body absorb vegetable crops potassium above nitrogen. Research shows that, in nitrogen phosphorus, potassium fertilizer based on content of notrite reduced can make the spinach, lettuce of 12.9% – was content of notrite reduced 12.0 – was 21.4%, the decrease of nitrate celery with the increase of k increased. Only with potassium fertilizer form supplements can’t satisfy the need to grow vegetables, increasing the amount of fertilizer.