What is organic fertilizer, and how much is used in vegetable production?

Vegetables are a food that people cannot do without; some people feel out of sorts if they go a day without eating vegetables. In the process of growing vegetables, fertilizing is an indispensable step; only with fertilizer can vegetables grow well and achieve high yields. Among them, organic fertilizer is one of the more widely used types. Let us take a look together below at what organic fertilizer is and how much is used in vegetable production.

1. What is organic fertilizer?

Organic fertilizer refers to carbon-containing materials whose main source is plants and/or animals and whose main function is to be applied to the soil to provide plant nutrients. According to the resource characteristics, properties and functions, and composting methods of organic fertilizers, they can be summarized into ten major categories: manure and urine fertilizers, compost and retting fertilizers, straw fertilizers, green manures, soil and miscellaneous fertilizers, cake fertilizers, sea fertilizers, humic acids, agricultural and urban waste materials, and biogas fertilizers. Because of the lasting nature of nutrient release and their eco-friendliness, organic fertilizers occupy an increasingly large proportion in agricultural production practice, especially in vegetable production.

2. How much organic fertilizer is used in vegetable production?

The maximum application rate of organic fertilizer should be based on the standard of meeting crop nutritional needs. Cake fertilizer, chicken manure and others have relatively high nutrient element contents; if the one-time basal application rate is too large, it easily causes fertilizer burn, promotes soil nitrification, and increases the nitrate content of vegetables. Therefore, when compost based mainly on chicken manure is used as a basal fertilizer, for low-fertilizer-demand vegetables such as melon, watermelon, tomato and legumes, the application rate generally should not exceed 7 500kg/hm2, and for high-fertilizer-demand vegetables such as cucumber, eggplant and pepper, it generally should not exceed 15t/hm2.

3. Other precautions for the use of organic fertilizer in vegetable production

1. Organic fertilizer must be fully decomposed. Organic wastes such as livestock and poultry manure and crop straw may contain relatively many pathogens, insect eggs, weed seeds and so on, which can easily cause vegetable diseases and insect pests; in addition, they can also spread through vegetables some diseases harmful to human health. Moreover, organic waste applied directly will continue to ferment in the field, compete with vegetable roots for oxygen, and generate a large amount of heat, easily causing seedling burn. Therefore, applying fully decomposed organic fertilizer is advocated, which can avoid the above harmful phenomena to the greatest extent. Vegetable growers in some areas have the habit of applying semi-decomposed organic fertilizer, but semi-decomposed organic fertilizer should be kept at a certain distance from the roots.

2. Organic fertilizer should be applied in reasonable combinations. Only by reasonably combining organic fertilizer with organic fertilizer, and organic fertilizer with chemical fertilizer, can the advantages of combining slow-release and quick-acting fertilizers be fully brought into play and the growth and quality of vegetables be regulated. For example, sheep manure has the highest nutrient content among livestock manures, decomposes relatively quickly, and has a relatively strong fertilizer effect; to achieve a balance of fertilizer effects, pig manure or cow manure should be added to sheep manure and applied as a mixture. Human manure and urine are quick-acting organic fertilizers, and when applied they should be combined with coarse organic fertilizers and phosphorus and potassium fertilizers. Some organic fertilizers have a very high carbon-to-nitrogen ratio; after application, soil microorganisms compete with crops for nitrogen, causing nitrogen deficiency, so an appropriate amount of chemical nitrogen fertilizer needs to be applied together. Combining organic fertilizer with phosphate fertilizer helps improve the fertilizer effect of phosphate fertilizer, and combining organic fertilizer with biological fertilizer also helps improve fertilizer efficiency.