Detailed Explanation of the Key Points of Forage White Clover Sowing Technology
White clover is a clover of the legume family and a perennial forage. Its stems grow creeping, 30-60 cm long, the main root is short, the lateral roots are well developed, and there are root nodules for nitrogen fixation. White clover prefers a cool and humid climate, is relatively shade-tolerant and moisture-tolerant, and its heat tolerance and cold tolerance are stronger than those of red clover. It can be planted in mountainous areas, hills, and orchards and tea gardens in the south. It has low requirements for soil and strong acid tolerance; it can even grow in soil with a pH value of 4.5, and it is not tolerant of saline-alkali soil. White clover fresh grass is rich in crude protein, and all kinds of livestock and poultry like to eat it. It can be cut for fresh grass 3-4 times each year, with a general yield of 3000-4000 kg per mu.
I. Growth Characteristics of White Clover
1. Perennial plant. White clover is a perennial-rooted plant and, with proper management, can continue growing for more than 10 years.
2. Good shade tolerance. It can grow normally under an environment with 30% light transmittance, and is relatively suitable for planting in mature orchards such as citrus orchards.
3. Good invasiveness. After white clover forms a turf, it has relatively well-developed lateral roots and creeping stems, and has stronger competitiveness than other weeds.
4. Wide adaptability. It has a certain degree of cold tolerance and heat tolerance, and a wide range of requirements for soil pH value, reaching 4.5-8.5. More than 99% of the soil pH value in Lishui City is below 7, so there is no problem planting it in the vast areas of Lishui.
5. High ornamental value. It blooms early, has a long flowering period, and has beautiful leaf shapes; after forming a turf, it can achieve a good landscape effect. The 30 mu of white clover planted in the peach orchard of Jiukeng Village, Liandu District has already shown a good ornamental effect, attracting many people to view peach blossoms, enjoy the green space, and take photos; the photos taken have very beautiful colors.
II. White Clover Sowing Technology
1. Sowing and seed treatment. The best time to sow white clover is in spring and autumn, and the optimum growth temperature is 19-24°C. Spring sowing can be done from the end of March to the end of April, and sowing can be done once the temperature stabilizes above 15°C. Autumn sowing generally starts in mid-to-late September. Before sowing, the seeds should be soaked. Add 1.5 jin of water per jin of seeds, plus 1 g of ammonium molybdate, and soak the seeds for 12 hours. Add 5-10 kg of calcium magnesium phosphate fertilizer plus 5-10 kg of fine soil or yellow sand, mix evenly, and then sow.
2. Land preparation. White clover seeds are very small, and the seedlings have poor ability to emerge through the soil. Before sowing, the land must be leveled and harrowed finely to facilitate seedling emergence. In areas with heavy clay soil and high precipitation, ditches should be opened and raised beds made to facilitate drainage. For mountain planting using fresh grass, it is advisable to choose relatively shady sections or sections with relatively moist soil. For interplanting in orchards, before sowing it is necessary to weed and loosen the soil between the fruit tree rows, level the land, and sow 1-2 days before rain.
3. Planting method. For planting between fruit tree rows, broadcasting or drilling can be used; for drilling, leave a row spacing of 15 cm. Sowing should be shallow rather than deep, generally 0.5-1.5 cm. For single-species sowing, the sowing rate is 0.5-0.75 kg per mu, by broadcasting or drilling, with a row spacing of 30 cm for drilling. It is better to sow after mixing the seeds with an equal amount of fertile soil. When mixed-sowing with tall fescue, ryegrass, and others, the sowing rate should be appropriately reduced. During the seedling stage, weeds should be removed in a timely manner to help white clover form a turf.
4. Fertilization. White clover belongs to the legume family and has its own nitrogen-fixing ability, but during the seedling stage the rhizobia have not yet formed, so a small amount of nitrogen fertilizer needs to be supplemented. Applying a small amount of nitrogen fertilizer helps strengthen the seedlings, and increasing the application of phosphorus and potassium fertilizers has a very good yield-increasing effect. After the turf is formed, only phosphorus and potassium fertilizers need to be supplemented. Before sowing, apply 20-25 kg of superphosphate per mu, as well as a certain amount of barnyard manure as base fertilizer. If the plants are short and the leaf color is yellow at emergence, apply a small amount of nitrogen fertilizer. Generally, 15 days after emergence, apply 2.5 kg of urea, 5 kg of potassium fertilizer, and 5 kg of calcium magnesium phosphate fertilizer to promote strong seedlings and increase grass yield.
5. Field management. White clover grows slowly during the seedling stage and is easily harmed by weeds, so weeds should be frequently removed during the seedling stage, especially for spring-sown fields. When sown in September, it buds and blooms in April of the following year, and reaches full bloom in mid-May. At the flowering stage, the grass layer height is 15-20 cm, which is the suitable period for mowing and utilization. After mowing, its regrowth ability is strong, quickly forming a second grass layer to cover the grassland. In high-temperature seasons, white clover stops growing. In the 2-3 years after forming a grass layer cover, large weeds should be removed in a timely manner. If missing plants occur due to high summer temperatures and drought, reseeding can be done in autumn to restore grassland productivity. If planted on a large scale as grazing land, light grazing can be carried out 1-2 months after sowing, when weeds are 20-25 cm high, to inhibit weed growth. White clover has few diseases, but if harvesting is not timely, brown spot disease and powdery mildew sometimes occur. It can first be mowed and utilized, and then controlled with Bordeaux mixture, lime sulfur mixture, or carbendazim, and others.
6. Mowing and utilization. When the height grows to about 20 cm, mow the grass. It can be mowed 3-4 times a year, and the stubble should not be lower than 5 cm when mowing to facilitate regrowth. Place the cut grass under the fruit tree canopy or between plants, and cover it with soil before winter so it rots into high-efficiency organic fertilizer. White clover fresh grass is rich in crude protein, and all kinds of livestock and poultry like to eat it. White clover is often used as the main planted grass species on grazing land. White clover and other clovers are often used with ryegrass to establish mixed-sown grassland for grazing cattle and sheep. In the agricultural areas of the middle and lower reaches of the Yangtze River, it is mostly mowed to feed pigs, cattle, fish, and others. White clover is tolerant of trampling, spreads quickly, and has strong competitiveness with weeds. Moderate grazing is conducive to the growth of white clover and the formation of a grass layer. Excessive single feeding of white clover to livestock and poultry can cause bloat, so it should be fed together with gramineous forage. Cut fresh grass 4-5 times each year, with a yield of 3000-4000 kg per mu.