Detailed Explanation of Six Key Points for Field Management of Patchouli
1. Loosening soil and earthing up.
During the growth process, patchouli should also be frequently loosened and earthed up. This not only loosens the soil and facilitates air circulation, but is also one of the important measures for making the plants taller, expanding the area for nutrient absorption, and increasing yield. During spring and summer, rainfall is abundant and the soil tends to become compacted, so at this time the soil should be frequently loosened together with weeding. At the same time, in order to accelerate the decomposition of organic fertilizer and protect plant growth, the muddy soil in the furrows should also be frequently dug up and earthed up around the base of the plants, which can promote more branching. After the Beginning of Autumn is the peak growth period for patchouli, and at this time strong winds often occur, making the plants prone to lodging. In order to prevent the plants from being blown over by the wind, a major earthing up should be carried out once at this time, so that new roots go deep into the soil and the plants become robust and stable.
2. Irrigation and drainage.
The amount of soil moisture directly affects the growth and development of patchouli. When soil moisture is insufficient, patchouli is prone to wilting, with reduced yield in mild cases and death in severe cases; when there is too much water, it causes excessive growth of stems and leaves, and may even lead to pests and diseases; if waterlogging forms, root asphyxiation due to insufficient oxygen can cause poisoning and death. Therefore, during the cultivation of patchouli, timely and appropriate irrigation and drainage should be carried out according to the water requirements of the patchouli plant and the soil moisture conditions. Under normal circumstances, water once each morning and evening, but the specific number of waterings and the amount of water applied must be determined according to the local climate and the water-holding capacity of the soil. During the growth process, if drought occurs and the bed surface turns white, water should be diverted for irrigation once every 5-8 days, introducing water into the furrows to a depth of 1/2-2/3 of the bed height, allowing the water to slowly seep through until the bed surface is moistened. If there are no conditions for diverted irrigation, then in addition to watering in the morning and evening each day, add one more watering in both the morning and afternoon, and the watering should penetrate thoroughly. During the rainy season or when heavy rain occurs, attention should be paid to drainage. Therefore, when planting patchouli in paddy fields, building high beds and deep furrows is precisely to prevent excessive rainwater accumulation from affecting the normal growth of patchouli. The experience of planting patchouli in paddy fields in Shipai, Guangzhou, is very good: storing water about 20 cm deep in the furrows, in addition to maintaining moisture through soil capillary action, when the temperature is high, the sun is strong, and evaporation is great, the water can also be sprayed onto the stems and leaves at any time. Besides accelerating the plant's water absorption to replenish the large consumption of water, this method can also lower the local atmospheric temperature of the planting site and increase the relative air humidity, which is very favorable for the growth of patchouli.
3. Fertilization.
Patchouli is a crop with a short cycle and high yield, and it is also a crop with a relatively large fertilizer requirement. Therefore, usually on the basis of applying sufficient base fertilizer, reasonable topdressing is also needed to obtain high yield. The medicinal part of patchouli is the aboveground part of the whole plant, so throughout the entire growth period, nitrogen fertilizer and compound fertilizer should be the main types applied. In the whole growth cycle, fertilizer is generally applied 3-5 times and bran water once. The interval between fertilizations depends on the length of the growing period in different production areas. In the suburbs of Guangzhou, fertilizer is applied once about every 60 days. The first fertilization is carried out after cuttings or planting have taken root and survived. The concentration of this fertilization should be light, and human and livestock manure urine water at 1:10-1:20 is sufficient. In dry seasons, more water-based fertilizer should be applied, and pig and cattle pen manure fertilizer can also be applied. Subsequent fertilization can be carried out at 3000 kg of bio-organic fertilizer per mu. However, when fertilizing, it should be taken into account that the organic matter content in bio-organic fertilizer is relatively high, the available nutrient content is relatively low, and the fertilizer effect is released relatively slowly, so sometimes part of the urea or compound fertilizer with a higher nitrogen content needs to be added (such as Norwegian compound fertilizer, N:P:K=15:15:15), especially during the regreening stage and the seedling strengthening stage after planting. After planting, nitrogen fertilizer should be applied lightly, with 3.5 kg of urea per mu diluted 1000 times and sprayed, or 25 kg of decomposed soybean bran per mu soaked in 6-7 times its amount of boiling water and then sprayed. After that, apply 10 kg of compound fertilizer per mu every 1 month for 3-4 consecutive times. Fertilization should follow the principle of light first and then concentrated, and frequent application in small amounts.
4. Shading.
During the seedling stage and the early stage after planting, patchouli should be covered with shade netting on the bed surface, and a shade net with 50% shading density can be selected for building a shed. The height of the shade shed should be sufficient to facilitate manual management.
In order to make full use of soil fertility, space, and light energy, medicinal growers can use intercropping with tall-stemmed crops to achieve the purpose of shading. It is best to intercrop vegetables between the rows of patchouli plants, such as cucurbits, ginger, Chinese cabbage, etc. Through intercropping, on the one hand, fertilizer can be added, and on the other hand, weed growth can also be suppressed. In addition, vines such as loofah, winter melon, and bitter melon can also be planted first between the rows of patchouli plants, using the melon trellis to shade the patchouli seedlings, which is very favorable for the growth of patchouli.
5. Frost prevention.
For patchouli that needs to overwinter, especially young small plants planted in summer and autumn, cold resistance is poor, so in areas with frost, by early winter, grass should be covered or sheds built to prevent frost, or on the north wind side, plastic film should be added to keep warm and prevent freezing damage. It is best to apply pig and cattle pen manure fertilizer in late autumn, add burnt soil ash, and earth up with burnt mud to keep warm.
6. Topping.
Topping is a yield-increasing measure that uses the correlations in plant growth to regulate and redistribute nutrients within the plant and promote the growth and development of the medicinal part. According to the growth condition of the patchouli plants, appropriately picking off the terminal buds promotes more branching growth, and this can also ensure that the existing branches and leaves grow thicker and stronger, thereby obtaining medicinal material of high yield and good quality.