How to Correctly Use Organic Fertilizer in Vineyards

How to Use Organic Fertilizer in Vineyards

Grapes are a crop that requires intensive cultivation. In the process of planting and management, fertilization is an important part of production management. Reasonable fertilization can not only improve grape quality and profitability, reduce costs, but also regulate soil structure and improve grape development and nutritional conditions. At present, grape production commonly suffers from excessive use of chemical fertilizers and indiscriminate supplementation of trace elements, while neglecting the role of organic fertilizer in increasing yield, improving quality, and building soil fertility. Correct use of organic fertilizer will be the guarantee for vigorous grape growth, normal fruiting, and excellent quality.

1 Benefits of Using Organic Fertilizer

There are 4 benefits of applying organic fertilizer to vineyard soil: ① Organic fertilizer contains abundant trace elements, with many types and good activation properties, which facilitates the balanced absorption of various elements by plants. ② It has lasting fertility and no pollution, making it a reliable fertilizer for producing organic, green, and pollution-free food. ③ Organic fertilizer can be converted into organic matter in the soil, which not only promotes the formation of soil aggregate structure and makes the soil loose and breathable, but also binds excess fertilizer in the soil, improving fertilizer utilization efficiency, reducing fertilizer damage, and extending fertilizer efficacy. ④ The purpose of using organic fertilizer is not the "fertilizer" itself, but mainly to improve the soil. Extensive use of organic fertilizer can reduce the amount of chemical fertilizer used and play a role in environmental protection.

2 Selection of Organic Fertilizer

Organic fertilizer is processed from biological substances, animal and plant waste, and plant residues. Toxic and harmful substances have been eliminated, and it is rich in beneficial substances, organic acids, peptides, etc., as well as abundant nutrient elements such as nitrogen, phosphorus, and potassium. There are 3 commonly used types of organic fertilizer:

2.1 Commercial organic fertilizer Generally, this is organic fertilizer that has undergone biological treatment by manufacturers. After high-temperature treatment, pests, diseases, and weed seeds are basically killed. Commercial organic fertilizer produced by legitimate manufacturers can basically be used with confidence. It is best to choose organic fertilizer specifically designed for vineyards.

2.2 Composted manure Commonly known as farmyard manure, it is made by composting manure and straw. If composted well, it can also be used with confidence. Considering that manure supplied by livestock farms may have strong acidity or alkalinity, heavy metals, antibiotics, etc., which can affect vineyard soil and fruit quality, and that insufficient decomposition can burn grape roots and may also bring pests and diseases, it is not recommended to compost manure yourself.

2.3 Green manure This refers to green plants that are grown and then returned to the field. It is recommended that growers use the vineyard sod-culture method, which plays a positive role in lowering soil temperature, increasing vineyard humidity, preserving soil moisture, and increasing soil organic matter content. According to relevant data, in sod-cultured vineyards, soil organic matter does not increase noticeably within 1~2 years, but from the 3rd year onward, soil organic matter content increases significantly. Commonly used green manure plants include mung bean, clover, and ryegrass.

It is recommended to use a new type of organic fertilizer: biochar. Biochar is the product of carbonization and decomposition of crop straw, wood processing waste, etc. under high-temperature and oxygen-limited conditions. It is rich in plant nutrients and micropores, not only having a large specific surface area, but also containing many oxygen-containing active groups on its surface. When applied to soil, it can increase beneficial soil microorganisms, increase soil water-holding capacity, improve soil fertilizer retention capacity, regulate soil pH, and fix carbon and nitrogen. When applied to soil, it can also adsorb heavy metals and organic pollutants in soil and wastewater. Its effective period lasts as long as 65~100 years, making it an ideal organic fertilizer.

3 Timing of Organic Fertilizer Application

Base fertilizer is the most important part of vineyard fertilization, and organic fertilizer is used as base fertilizer. In northern regions, September~October is best; in southern regions, October~November is best. At this time, fertilization only damages capillary roots, deep fertilization can be carried out, and the fertilization range can also be appropriately expanded, with no impact on fruit tree growth. For early-maturing varieties, apply after fruit harvest; for late-maturing varieties, apply after fruit ripening. At this time, a single fertilization can achieve the dual effects of fertilizing and loosening the soil.

4 Methods of Organic Fertilizer Application

Fertilization methods differ for grapes with different trellis shapes. For hedge-trained grapes, either side can be used. For trellis-trained grapes, it is best to dig trenches under the trellis; for those with few plantings, digging pits is best. The 2 commonly used methods are:

4.1 Strip trenching fertilization Dig strip-shaped trenches between tree rows, with a trench width of 30~40cm and a trench depth of 40~50cm. Grape roots grow in the 40~60cm soil layer, so too shallow or too deep will not be effective. Dig trenches on one side, and switch to the other side the next year. This not only maintains the balance of soil organic matter, but also helps protect grape roots. When digging trenches, pay attention to observation and never damage grape roots. Mix the fertilizer with soil and backfill. To induce roots to develop deeper into the soil and accelerate soil maturation, the soil at the bottommost layer when digging should be placed 10cm from the surface.

4.2 Ring trenching fertilization Dig a ring-shaped trench centered on the grapevine. The fertilization method and trench specifications are the same as the strip trenching fertilization method. The recommended method is alternate-row trenching fertilization, that is, in the 1st year, dig trenches and fertilize in rows 1, 3, 5 (odd-numbered rows)..., and in the 2nd year, dig trenches and fertilize in rows 2, 4, 6 (even-numbered rows).... After fertilizing in turn this way, not only has the soil throughout the vineyard been deeply turned and improved, but the workload of fertilization has also been reduced.

5 Precautions

(1) The organic matter content of medium-level soil is about 2%~3%. To increase organic matter by 1 unit per 667m3, about 3t of organic fertilizer is needed, and the use of organic fertilizer must be continuously supplemented. Therefore, organic fertilizer is best used every year, and the more the better. (2) It is advocated to apply organic fertilizer together with chemical fertilizer. According to the soil fertility conditions and yield level of the vineyard, appropriately increase the use of potassium fertilizer, and apply trace elements such as calcium, zinc, boron, and iron in combination. For chemical fertilizers such as urea, potassium dihydrogen phosphate, and superphosphate, they should be mixed with organic fertilizer or microbial fertilizer. The ratio of organic nitrogen to inorganic nitrogen is preferably 1:1, which is basically equivalent to a ratio of 1000kg of farmyard manure to 20kg of urea. (3) Fertilizer application should be combined with high-yield and high-quality cultivation and integrated water-fertilizer technology.