Key Technical Points and Implementation Methods for Soil and Water Conservation in Tea Gardens
Soil and Water Conservation Techniques for Tea Gardens
The control of soil and water loss in tea gardens should be based on the causes of local soil and water loss, and measures should be taken according to local conditions through engineering measures, agronomic measures and biological measures.
1. Engineering measures.
(1) Building contour terraces on steep-slope tea gardens.
Facts have proven that for tea gardens on steep slopes above 15 degrees, building terraces is the most effective measure to prevent soil and water loss. When building terraces, the terrace walls can be made of stone blocks, turf or raw soil; dig along the contour lines through the topsoil down to the subsoil layer, and make a slope base about 50 cm wide. Check promptly every year, repair any damage at any time, and promptly carry out various works of widening the terrace edge and maintaining the terraces.
(2) Establishing water storage and drainage systems.
Establishing a reasonable water storage and drainage system in a tea garden is another important engineering measure to prevent soil and water loss. During the construction of a tea garden base, scientific design and rational layout must be carried out in advance. The water storage and drainage system mainly includes intercepting ditches, isolation ditches, transverse ditches and longitudinal ditches. Intercepting ditches are dug to prevent floodwater and accumulated water from the rainwater-collecting area above the tea garden from flowing into the tea garden and causing soil and water loss; if there is no rainwater-collecting area above the tea garden, they need not be dug. The depth and width of intercepting ditches should be determined according to the size of the rainwater-collecting area above the tea garden, generally 50-100 cm deep and 40-60 cm wide, dug along contour lines; take the soil from the ditches and place it below the ditches to build a path, and connect both ends of the ditches with the longitudinal ditches of the tea garden to facilitate drainage. Transverse ditches are dug to intercept water flow within the tea garden. In terraced tea gardens, they are dug on the inner side of each terrace; in gentle-slope tea gardens, 1 ditch is set every 10-15 tea rows; if there is a transverse path at the hillside, a transverse ditch should also be dug above the path. The depth and width of transverse ditches are determined according to the slope, generally 30-40 cm in width and depth. Longitudinal ditches are mainly used to drain excess water from the tea garden and the water flowing out of intercepting ditches and transverse ditches, and are generally dug on both sides of the uphill paths and in particularly low-lying places in the tea garden. The depth and width of the ditches are determined according to the slope and the water-collecting surface of the tea garden, generally 40-50 cm. Longitudinal ditches should be connected with transverse ditches, and at the junctions, soil accumulation pits and earth dams should be built to reduce the flow speed of water in the longitudinal ditches and accumulate sediment, further improving the effect of soil and water conservation in the tea garden.
2. Agronomic measures.
(1) Contour planting and rational strip planting.
Whether in terraced tea gardens or sloping tea gardens, contour planting can effectively prevent soil and water loss; in particular, rational double-row strip planting and multi-row strip planting have an even better effect on preventing soil and water loss. The planting holes of each row in double-row strip planting and multi-row strip planting should cross each other and be arranged in a "∴∵" pattern, which can enable the tea plants to play a better role in soil conservation. For any tea rows with missing plants or gaps, efforts should be made to fill them in, to prevent soil and water in the tea garden from being lost through the gaps.
(2) Strengthening cultivation and expanding the canopy.
Young tea plants must undergo 3 rounds of formative pruning; mature tea plants should combine harvesting with nurturing, continuously expand the canopy, increase the shading density and green coverage of the tea garden, reduce exposed soil, and prevent rainwater from directly impacting the soil and causing soil loss.
(3) Mulching the ground with grass.
Mulching the ground with grass can not only prevent soil and water loss in tea gardens, but also increase soil organic matter and nutrient content, and improve soil fertility. In addition, mulching the ground with grass can also reduce the compaction intensity of tea pickers on the soil, inhibit weed growth in the tea garden and buffer excessive changes in soil temperature; it can keep warm and prevent freezing in winter, and prevent soil moisture evaporation in the dog days. Especially during the young stage, mulching the tea garden with grass should be done well. Mountain grass, rice straw, wheat straw, bean stalks, bagasse, green manure and so on can all be used as mulch material for tea gardens. In order to make grass mulching in tea gardens play a more effective role in soil and water conservation, the amount of dry grass in a picking tea garden must not be less than 800 kg per mu, and efforts should be made to complete the mulching before the rainstorms that cause the most serious soil and water loss arrive. After mulching a sloping tea garden with grass, soil should be pressed on top of the grass to prevent the mulch material from being washed away by water.
1. Engineering measures.
(1) Building contour terraces on steep-slope tea gardens.
Facts have proven that for tea gardens on steep slopes above 15 degrees, building terraces is the most effective measure to prevent soil and water loss. When building terraces, the terrace walls can be made of stone blocks, turf or raw soil; dig along the contour lines through the topsoil down to the subsoil layer, and make a slope base about 50 cm wide. Check promptly every year, repair any damage at any time, and promptly carry out various works of widening the terrace edge and maintaining the terraces.
(2) Establishing water storage and drainage systems.
Establishing a reasonable water storage and drainage system in a tea garden is another important engineering measure to prevent soil and water loss. During the construction of a tea garden base, scientific design and rational layout must be carried out in advance. The water storage and drainage system mainly includes intercepting ditches, isolation ditches, transverse ditches and longitudinal ditches. Intercepting ditches are dug to prevent floodwater and accumulated water from the rainwater-collecting area above the tea garden from flowing into the tea garden and causing soil and water loss; if there is no rainwater-collecting area above the tea garden, they need not be dug. The depth and width of intercepting ditches should be determined according to the size of the rainwater-collecting area above the tea garden, generally 50-100 cm deep and 40-60 cm wide, dug along contour lines; take the soil from the ditches and place it below the ditches to build a path, and connect both ends of the ditches with the longitudinal ditches of the tea garden to facilitate drainage. Transverse ditches are dug to intercept water flow within the tea garden. In terraced tea gardens, they are dug on the inner side of each terrace; in gentle-slope tea gardens, 1 ditch is set every 10-15 tea rows; if there is a transverse path at the hillside, a transverse ditch should also be dug above the path. The depth and width of transverse ditches are determined according to the slope, generally 30-40 cm in width and depth. Longitudinal ditches are mainly used to drain excess water from the tea garden and the water flowing out of intercepting ditches and transverse ditches, and are generally dug on both sides of the uphill paths and in particularly low-lying places in the tea garden. The depth and width of the ditches are determined according to the slope and the water-collecting surface of the tea garden, generally 40-50 cm. Longitudinal ditches should be connected with transverse ditches, and at the junctions, soil accumulation pits and earth dams should be built to reduce the flow speed of water in the longitudinal ditches and accumulate sediment, further improving the effect of soil and water conservation in the tea garden.
2. Agronomic measures.
(1) Contour planting and rational strip planting.
Whether in terraced tea gardens or sloping tea gardens, contour planting can effectively prevent soil and water loss; in particular, rational double-row strip planting and multi-row strip planting have an even better effect on preventing soil and water loss. The planting holes of each row in double-row strip planting and multi-row strip planting should cross each other and be arranged in a "∴∵" pattern, which can enable the tea plants to play a better role in soil conservation. For any tea rows with missing plants or gaps, efforts should be made to fill them in, to prevent soil and water in the tea garden from being lost through the gaps.
(2) Strengthening cultivation and expanding the canopy.
Young tea plants must undergo 3 rounds of formative pruning; mature tea plants should combine harvesting with nurturing, continuously expand the canopy, increase the shading density and green coverage of the tea garden, reduce exposed soil, and prevent rainwater from directly impacting the soil and causing soil loss.
(3) Mulching the ground with grass.
Mulching the ground with grass can not only prevent soil and water loss in tea gardens, but also increase soil organic matter and nutrient content, and improve soil fertility. In addition, mulching the ground with grass can also reduce the compaction intensity of tea pickers on the soil, inhibit weed growth in the tea garden and buffer excessive changes in soil temperature; it can keep warm and prevent freezing in winter, and prevent soil moisture evaporation in the dog days. Especially during the young stage, mulching the tea garden with grass should be done well. Mountain grass, rice straw, wheat straw, bean stalks, bagasse, green manure and so on can all be used as mulch material for tea gardens. In order to make grass mulching in tea gardens play a more effective role in soil and water conservation, the amount of dry grass in a picking tea garden must not be less than 800 kg per mu, and efforts should be made to complete the mulching before the rainstorms that cause the most serious soil and water loss arrive. After mulching a sloping tea garden with grass, soil should be pressed on top of the grass to prevent the mulch material from being washed away by water.