What are the raw materials for organic fertilizer? Farm-made organic fertilizer vs. commercial organic fertilizer
In what ways do farm-made organic fertilizer and commercial organic fertilizer differ? Because organic materials differ in composition and in the nutrients they release upon decomposition, their application requires attention to the advantages and disadvantages of each organic material, making up for shortcomings by drawing on strengths, and making the most appropriate blending and application, which will achieve twice the result with half the effort
In what ways do farm-made organic fertilizer and commercial organic fertilizer differ? Because organic materials differ in composition and in the nutrients they release upon decomposition, their application requires attention to the advantages and disadvantages of each organic material, making up for shortcomings by drawing on strengths, and making the most appropriate blending and application, which will achieve twice the result with half the effort. The application guidelines for several common organic materials are explained below:
I. Farm-made organic fertilizer:
1. Barnyard manure (manure type):
Pay attention to the application rate: barnyard manure contains relatively high amounts of salts and nitrogen. If unfermented fresh urine water is used, fertilizer burn or excessive nitrogen results easily occur; with long-term use of the solid and liquid portions of manure, care should be taken not to apply them in excess.
Best used as a base fertilizer: barnyard manure with higher nitrogen is suitable for use as a base fertilizer. In fruit tree applications, it must not be applied in large amounts before and after flowering, so as to avoid excessive nitrogen or, due to decomposition, causing flower and fruit drop or poor flowering; it should be applied earlier.
Combine with other organic fertilizers or plant residues: after barnyard manure is applied, it will decompose rapidly, and nitrogen loss can reach 2-30%; at high temperatures and in strong winds, the loss is even greater. Organic matter that is relatively acidic can be used to stabilize ammonium nitrogen and reduce ammonia loss. The nutrient-balanced fertilization method cannot be ignored, so the application of organic fertilizer should also emphasize the balance of nutrients. Plant residues are excellent material for absorbing and retaining the manure and urine of livestock and poultry, and they also offer considerable benefits and convenience for the application of organic fertilizer.
Pay attention to application hygiene and safety: when using animal manure organic fertilizer, care should be taken not to apply it on the soil surface, as it easily becomes foul-smelling and breeds insects. Treated manure can reduce this drawback, but it still needs to be covered with soil or turned under after application. Vegetable fields in particular need attention to hygiene and safety when using organic fertilizer, to prevent the breeding of parasites and pathogens.
2. Residues and compost:
Crop straw residues (such as rice straw, corn stalks, etc.) should be applied or worked into the soil as early as possible before sowing, to prevent nutrient elements (such as nitrogen, trace elements, etc.) from being absorbed and immobilized by decomposing microorganisms; otherwise, seedlings will be affected by the residues, causing nutrient deficiency and yellowing. Therefore, when applying undecomposed crop straw residues, they need to be combined with organic nitrogen fertilizer containing higher nitrogen.
Fields with poor drainage should reduce the large-scale application of crop residues or undecomposed compost. In poorly drained soil under anaerobic (oxygen-deficient) conditions, organic matter easily decomposes into harmful substances, which will cause damage to crop roots. Straw from diseased plants or from weeds that have set seed should not be applied directly, so as to avoid the breeding of pathogens and weed seeds; otherwise the loss outweighs the gain.
3. Green manure:
The selection of green manure crops needs to match seasonal growth: winter green manures, such as Chinese milk vetch (Astragalus sinicus), rapeseed, green-pod bean, alfalfa, etc., and spring-summer green manures, such as sesbania, sunn hemp, etc., require green manure varieties that grow well when planted in the appropriate season.
The selection of green manure crops needs to match the soil and the next crop: leguminous green manure is most suitable for soils deficient in nitrogen fertilizer and organic matter, especially upland crop fields. For paddy fields with plenty of nitrogen fertilizer, leguminous green manure needs to be matched to the soil, because legumes add too much nitrogen, which easily causes rice to produce ineffective tillers. Therefore, when planting leguminous green manure in paddy fields, it must be matched with the soil by reducing nitrogen fertilizer application; otherwise problems of excess nitrogen or rice blast easily occur.
Use green manure with caution on farmland with poor drainage. If it needs to be used, non-legumes such as rapeseed and radish may be chosen, and it is better to plant them until they have flowered and aged, because if they are too tender they decompose too quickly, which easily causes nutrient competition or toxic effects on the growth of crop seedlings.
II. Commercial organic fertilizer:
1. Peat:
Foreign peat is an organic fertilizer that has been used for a long time. Peat is the product of long-term deposition and transformation of ancient organisms, and after application it decomposes very slowly in the soil; it is the most effective material for increasing long-term soil organic matter. The degree of decomposition or transformation of peat products varies more or less among producing areas, because peat contains a high amount of humic acid, the essence of soil. Peat also contains yellow acid and humic gel, has a high organic matter content, and its ash content should not be too high. Peat is light in weight and acidic, but commercial products have already been neutralized and mostly have had the nutrients contained in the peat adjusted; it can be regarded as the most stable and difficult-to-decompose soil amendment. Adjusting the nutrients in peat is best done by adding easily decomposable organic materials, to make up for peat's need for difficult decomposition. "Peat moss" is often the product of plants being submerged in water for many years, and it is excellent for loosening soil and retaining water, but it differs from the "peat soil" formed by ancient organisms over tens of thousands of years. Both peat moss and peat soil are good soil amendments.
2. Animal waste:
This includes animal manure (chicken manure, pig manure, sheep manure, etc.), discarded residues (fish meal, bone meal, feathers, hides, etc.), and so on. The composition of manure types varies greatly in quality depending on the feed and the amount of added materials; for example, adding too much rice grain to chicken manure affects the composition content, so pay attention to purchasing quality. Fish residue and feather types both contain fairly high nitrogen; generally feather types contain very high protein and can be regarded as a nitrogen fertilizer source, and some commercial products decompose protein down to amino acids, becoming amino acid type nitrogen fertilizer. Bone meal contains relatively high calcium and phosphorus fertilizer and is a relatively slowly decomposing organic phosphorus fertilizer. Manure types (such as pig manure) as organic materials especially need attention to the problem of excessive heavy metal copper, because the chemical substances added to some feeds will affect the quality of the manure.
3. Plant and microbial residues or waste:
This includes the distinction between decomposed (or semi-decomposed) and undecomposed. The common decomposed and rotted compost varies in quality according to the materials used, the amount of nutrient content, and the difference in maturity. Generally, maturity is measured by the "carbon-nitrogen ratio," and the lower the "carbon-nitrogen ratio," the more mature it is.
Among dried microbial bodies, yeast powder is the most common, and it also contains a relatively large amount of nitrogen; it can be regarded as one of the important microbial materials and can also serve as a material to promote compost fermentation. Common undecomposed organic fertilizers include soybean cake, various seed residues, fibrous wood chips, etc. Bean cake residues are a fertilizer containing relatively high nitrogen, while hard shell residues are organic matter that is difficult to decompose and can be regarded as a good long-term soil amendment.
4. Extracted or concentrated organic fertilizer:
Among commercial products there are organic substances extracted from animals, plants, and microbial bodies, in liquid or concentrated powder form, containing various organic substances and nutrient elements (including trace elements), and even containing extracts such as enzymes, plant hormones, and antibiotics. Common ones include seaweed and fish extracts, which can be regarded as comprehensive nutrient agents.