Key Techniques for Plastic Film Mulch Cultivation of Spring Peanuts

The plastic film mulch cultivation technique for spring peanuts is one of the “Top Ten” advanced agricultural technologies promoted by the Ministry of Agriculture. It was introduced to our city for trials in 1998 and began demonstration and extension in 1999. Years of practice have proven that this technique is indeed an important measure for improving peanut yield and quality. 

I. Advantages of Plastic Film Mulch Cultivation of Peanuts 1. Plastic film mulching of peanuts can raise soil temperature by 3-4 degrees, maintain stable soil moisture, and keep the soil loose and free from compaction. 2. Plastic film mulching of peanuts favors soil microbial activity, promotes the effective transformation of soil nutrients, and prevents fertilizer leaching. 3. Plastic film mulching of peanuts can enhance seed germination vigor, increase the germination rate, and shorten the emergence time. According to trials, the germination rate is generally increased by 5-10%, and the emergence time is advanced by 5-7 days. 4. Plastic film mulching of peanuts can promote vegetative growth, with a well-developed root system and early and abundant nodule formation, resulting in vigorous growth in the early growth stage. According to measurements, at 30 days after sowing, the growth amount increases by 1 fold. 5. Plastic film mulching of peanuts can promote earlier flowering, increase the number of flowers, increase the number of effective flowers, improve the pod-setting rate, and increase the number of pods per plant and the number of full pods. According to trials, mulched peanuts generally have 2 more pods per plant and 1.04 more full pods than unmulched peanuts, with a yield increase of 41.37 kg per mu. 

II. Plastic Film Mulch Cultivation Techniques for Peanuts

1. Soil selection and land preparation: The soil should preferably be loam or light sandy loam with medium or higher fertility and a relatively deep soil layer, and should be fresh land or rotated land with good drainage and irrigation conditions. Deep plowing and fine harrowing should be carried out to remove residual stubble and stones, achieving a fine, crumbly soil texture and a level soil surface.

2. Fertilization: For mulched peanut cultivation, all fertilizers for the entire growth period are applied before sowing. Organic fertilizer can be applied throughout the entire layer, while chemical fertilizer can be broadcast together with organic fertilizer before bed formation, or concentrated on the bed surface after bed formation, and then mixed evenly with the surface soil of the bed through fine tillage. The application rate depends on soil fertility conditions. Generally, for a yield of 250­-380 kg of peanut pods per mu, 11.3-18.5 kg of pure nitrogen, 2.0-3.7 kg of pure phosphorus, 4.4-11.9 kg of pure potassium, and 36.2-8.54 kg of pure calcium are required. The nitrogen, phosphorus, and potassium ratio used in plastic film mulch technology is 6:1:4. Generally, 1500-2500 kg of farmyard manure, 1500-2000 kg of human and animal excreta, 30-50 kg of ternary compound fertilizer, or 20-25 kg of compound fertilizer, and 50 kg of lime are applied per mu.

3. Seed selection and treatment: Seeds should preferably be large, plump, free from pests and diseases, and have a germination rate above 95%. It is best to use chemical treatment to protect the seeds, and to carry out pre-sowing osmotic treatment before sowing. Before sowing, 50-100 g of 50% carbendazim powder is used per mu for seed dressing.

4. Sowing time, sowing method, and density: Sowing is generally required from late February to early March, seizing the “cold tail and warm head” period to sow on sunny days. The planting method adopts the small-bed double-row close planting method, with a bed and furrow width of 80 cm, a bed height of 30-35 cm, and a bed surface width of about 45 cm, formed into a trapezoidal bed. Two seeds are sown per hole, with a hole spacing of 12-14 cm and a sowing depth of 3-5 cm. It is best to use a hole punch to make the holes. After sowing and covering with soil, the bed surface should remain level, with fine soil particles, and the furrows should be flat, straight, and unobstructed to facilitate film covering and drainage. The planting density is 18,000-22,000 plants per mu.

5. Use of herbicides: Acetochlor or butachlor is selected as the herbicide. Acetochlor is used at 200 g per mu, or butachlor at 400 g per mu, diluted with 60-80 kg of water, and evenly sprayed on the bed surface and both sides after sowing, with film covering immediately after spraying.

6. Film covering: After sowing, first use a hoe to pull the soil from the two sloping sides of the bed at 2/3 of the distance from the furrow bottom into the furrow, to a depth consistent with the furrow bottom. Then a group of three people carries out manual film covering: one person lays the film along the bed in front, while the other two stand in the furrows on both sides of the bed, gently stepping on the film with their feet to press the plastic film vertically down, pulling it tight and flat so that the film closely adheres to the bed surface; at the same time, they use hoes to build up soil from the furrow and press it onto both sides of the film, pressing it tight and firm to restore the original shape of the bed. Every 0.5-1 m or so, a small mound of soil is placed on the bed surface to prevent wind and protect the film. Film laying and film pressing should be coordinated, laying the film while pressing it and moving along. Care should be taken during operation to avoid tearing or stepping through the film. Film laying should avoid windy periods and should be done with the wind.

7. Film perforation: When the peanut cotyledons emerge, use a blade or sharp knife (or fingernail) to cut the plastic film directly above the cotyledons into a cross shape, about 4 cm in length. Film perforation is done in two stages: the first perforation is when 70-80% of the cotyledons have emerged, and the second is when all cotyledons have emerged. Do not lift or remove the film.

8. Strengthen field management and harvest in a timely manner: First, check the film covering quality after sowing to see whether the film has been lifted by wind; second, check seedlings and replant early; third, promptly check and free seedlings trapped under the film; fourth, use soil to suppress weeds; fifth, pay attention to controlling pests and diseases such as white grubs, aphids, scab, leaf spot, and rust; sixth, apply topdressing reasonably, with foliar topdressing in the middle and late growth stages using 0.1-0.3% potassium dihydrogen phosphate or 2% superphosphate clear liquid mixed with 1% urea solution; seventh, pay attention to drainage and irrigation, generally requiring dry seedlings, moist pegs, and moist pods; eighth, peanut harvest should be carried out at the appropriate maturity stage, around mid-to-late July.