Connotation and cultivation techniques of the new triple cropping model of dryland wheat variety "wheat/jade/bean"

Southern 14 provinces, municipalities and autonomous regions are the main agricultural producing areas in China, especially in the southwest region, which has a large proportion of hilly and mountainous dry land and a high degree of multiple cropping, and is a typical dry farming and multiple cropping agricultural area in southern China. For a long time, wheat/jade/potato, oil-jade/potato, sugarcane/sweet potato, etc. It is planted twice a year and three times a year in the southwest dry land of China, with an annual planting area of 53.7 million mu. In recent years, with the improvement of farmers' living standards and diet structure, the production status of sweet potato has gradually changed from staple food to miscellaneous grains. In addition, there are some problems in planting, harvesting and handling, such as high labor intensity, difficult storage and low efficiency, which can not meet the needs of farmers under the new situation of modern agricultural development, and the production area is gradually shrinking. In order to meet farmers' demand for new production technology in the new period and realize agricultural income increase and efficiency increase, Sichuan Agricultural University, on the basis of summarizing the disadvantages of the "wheat/jade/potato" model, cooperated with Sichuan Agricultural Technology Extension Station to form a new model of high-efficiency ecological multiple cropping in dry land-"wheat/jade/bean". After nearly 10 years of research, demonstration and popularization, this model has initially formed a comprehensive supporting cultivation technology system of "wheat/jade/bean" including seed treatment technology, variety sowing date adjustment technology, chemical control technology, population allocation technology and agricultural machinery and agronomy supporting technology. In 2007-2008, it was listed as the main technology of dominant agricultural products (soybeans) by the Ministry of Agriculture, and was listed as the new technology widely used in Document No.1 by Sichuan Province, the eight new technologies and processes of water-saving agriculture in Sichuan Province, and the main technology in the 300 Project. In 2007, the planting area reached 26 1.3 million mu, and the average yield per mu was 1.38. 2 kg. In 2008, the planting area reached 3.5 million mu, and the average yield per mu reached 1 18.3kg. Since the demonstration and popularization in Sichuan Province in 2003, this technology has developed very rapidly, and its area has increased year by year, which is deeply loved by the people. It has played a very important role in increasing local grain production and farmers' income, and is becoming a practical new technology to promote the development of modern agriculture in multi-cropping areas in southern China.

First, the connotation of "wheat/jade/bean" model

The new triple cropping system "wheat/jade/bean" in dry land is a multiple cropping system in which soybean in "wheat/jade/potato" mode replaces sweet potato in continuous interplanting rotation under the condition of integrating no-tillage, straw mulching and direct seeding of crops, and its multiple cropping mode is "wheat/corn/soybean". As a new dryland planting model integrating drought resistance and disaster reduction, land use and tillage, conservation tillage and light tillage, this model embodies the connotation of developing high-quality, high-yield, high-efficiency, ecological and sustainable agriculture, promotes the optimal adjustment of planting structure, and is an important technical measure to increase production and income of dryland agriculture.

"Wheat/Jade/Bean" model has the technical characteristics of "five changes, four reductions, three increases, two benefits and one liter". Five changes: sweet potato changed into soybean, intercropping and interplanting, spring sowing changed into summer sowing, sparse planting changed into dense planting, furrowing and ridging changed into no-tillage straw mulching; Reduce: reduce material input, reduce labor intensity, reduce soil erosion and reduce environmental pollution; Three increases: strengthening drought resistance, increasing annual output and increasing farmers' income; Two advantages: it is conducive to resource conservation and environmental friendliness; First, promote the sustainable development of dryland agriculture.

Second, the advantages of the "wheat/jade/bean" model

1. The new model integrates no-tillage, straw mulching and direct seeding technology, saving labor and cost, achieving high benefits, increasing farmers' income and achieving remarkable economic benefits. According to the investigation and statistics of Sichuan Agricultural Technology Extension Station in recent three years, the average yield per mu of new model soybean is 125.62kg, and the output value per mu is 4 16.99 yuan, while the raw grain per mu of sweet potato is 22 1.29kg, and the output value per mu is 290.6 yuan, which is higher than that of sweet potato. Compared with the "wheat/jade/potato" model, the new model saves 5.9 workers per mu after returning no-tillage straw to the field, and can increase the income per mu by 1 18 yuan according to the 20 yuan of each worker. Planting soybeans can save seeds, fertilizers and pesticides per mu than planting sweet potatoes 15 yuan. On the whole, the economic benefit of the new wheat/jade/bean model is 259.35 yuan/mu higher than that of the traditional wheat/jade/potato model.

2. Fertility and outstanding ecological benefits. The new model adopts no-tillage straw mulching cultivation, which effectively reduces soil erosion. The research shows that compared with the "wheat/jade/potato" model, the new model can reduce soil erosion by 65,438+00.6% and surface runoff by 85. 1%. The soil total nitrogen content of maize and soybean increased by 4. 1 1% and 7.29% respectively, and the nitrogen utilization rate of maize increased by 39.25438+0%. In addition, in the new model, wheat, corn and soybean are rotated in micro-area, which effectively avoids the obstacles caused by continuous soybean cropping, reduces the harm of pests and diseases, and realizes the increase of production and income.

3. Relieve the contradiction between supply and demand, with obvious social benefits.

China is the largest soybean importer in the world, with a perennial supply-demand gap of 25 million tons, and its import volume reached 37.436 million tons in 2008. In recent years, the annual demand for soybeans in Sichuan Province is gradually increasing, and the gap between production and demand is more than 6.5438+0.5 million t. The new dry land model with soybeans as the main body can save labor, reduce labor intensity, alleviate rural labor shortage and promote rural labor transfer. By expanding soybean planting area and increasing total soybean output, we can realize the adjustment of agricultural industrial structure, alleviate the contradiction between supply and demand of soybeans in China, improve people's dietary structure and promote the rapid development of soybean industry and animal husbandry.

4. Drought resistance, disaster avoidance and good disaster reduction effect According to the statistics of Sichuan Agricultural Technology Extension Station for three consecutive years from 2006 to 2008, under the conditions of drought and earthquake disaster, the harvest area of soybean intercropping in the whole province reached 6.5438+0.294 million mu, 2.65438+0.3 million mu and 3.5 million mu respectively, with an average yield of 654.38+0.2562 kg per mu, indicating that it is new.

Third, the popularization and application prospect of "wheat/jade/bean" model

Sichuan has a large proportion of dry land and a high multiple cropping index. The existing dry land area is 27.387 million mu, and the area of double cropping and triple cropping in a year is 65.438+0.9/kloc-0.7 million mu, of which the planting area of sweet potato is about 654.38+0.2 million mu, and the annual output of fresh potato is about 654.38+0.5 million t. With the development of pig breeding in Sichuan Province from traditional free-range to intensive and large-scale, the original potato blocks and potatoes are used. In addition, wheat-corn, wheat-sweet potato and other double cropping patterns will be changed to "wheat (potato)/jade/bean" triple cropping system, and the original four-cropping pattern with summer, autumn and winter beans will be gradually optimized to triple cropping soybean, with a development potential of about 2 million mu. Therefore, after 8 ~ 10 years' development, by the end of the Twelfth Five-Year Plan, the planting area of interplanting soybean in Sichuan Province is expected to reach 100000 mu, which can produce about160000 tons of soybeans, directly increasing farmers' income1264 million yuan, saving 57 million workers and saving money. Chongqing, Guizhou, Yunnan, Hubei, Guangxi and other provinces (regions) have also successfully interplanted soybeans with corn. If all the existing corn production modes are developed into the intercropping mode of jade beans, the potential area of soybean intercropping in southern China is 72.024 million mu, and soybean1.15238 million tons can be produced every year, increasing the income by18679 million yuan.

Fourth, the cultivation technology of "wheat/jade/bean" mode.

1. The standard out-of-box micro-area rotation adopts the strip 2m out-of-box mode, 1m (or 1. 17m) plants 5 rows (or 6 rows) of wheat, and 1m (or 0.83m) plants 2-3 rows of soybeans after the wheat is harvested.

2. No-tillage direct seeding, that is, covering wheat straw after harvesting, and covering soybean straw with no-tillage direct seeding; After the corn is harvested, it is directly cut down and covered with empty rows. When wheat is sown, no-tillage direct seeding is implemented, and corn stalks cover wheat rows.

3. Choose improved varieties and pay attention to the space-time collocation of three crops when choosing reasonable varieties. Soybean varieties with developed main stems, stout stems and large grains should be selected, such as Gong Xuan 1 and Nandou 12. Wheat varieties with high yield, high quality and strong stress resistance should be selected; It is advisable to choose middle-maturing maize varieties with high quality, high yield, high resistance (disease and insect resistance, drought resistance and lodging resistance) and compact plant type.

4. Sow soybeans in time and plant them in reasonable density. The sowing period is from May 25th to June15th. According to the local weather forecast, the seeds should be planted before or after the rain. Selecting seeds before sowing, removing seeds with incomplete grains, mottled and diseased spots, stirring and dissolving with 50% carbendazim 5g/kg seeds and a little water, then evenly dressing seeds, drying and sowing. The planting density of ditch and grassland is 6 000 ~ 7 500 plants per mu, with the row spacing within the belt of 0.33m and the hole spacing of 0.4 ~ 0.5 m; Two sets of soil (and above) have 7 000 ~ 9 000 plants per mu, with an inner row spacing of 0.33 m and a nest spacing of about 0.3 ~ 0.4 m. When sowing, the seeds are separated from the fertilizer by digging nests. Fertilizer is applied to both sides of the nest near the corn, seeds are scattered to the other side of the nest, and 5-6 seeds are scattered in each nest. After sowing, cover with fine soil. When it grows to three leaves, the seedlings should be evenly distributed in time, leaving only three plants in each nest.

The sowing period of wheat is from 10 to 1 10. Loam and sandy soil are sowed by seeder, and clay is sowed by sowing or digging ditches. When sowing, firstly, the corn stalks are fished out, evenly sown and covered, and 5-6 kilograms of seeds are consumed per mu; Machine seeding, digging or cutting the pit, the hole spacing is 0.13-0.17m, the row spacing is 0.2m, 8-9 seeds are sown in the hole (4-5 seeds are reserved in the hole), and 70,000-80,000 basic seedlings are reserved per mu.

Corn should be sown in time according to local conditions, in hilly areas in mid-March and in mountainous areas in late March. The sowing method is sowing or fertilizing and transplanting. When sowing or transplanting, the distance between the two sides of the wheat belt is 0. 17 ~ 0.2m, the row spacing is about 0.6m, and the hole spacing is 0.4~0.47m Two plants are left in each hole, and 2800 ~ 3000 plants are planted per mu.

Weeds are removed by chemical herbicides or manually before sowing or during the crop growing season. Herbicide can be selected from 25% Zuo Dan EC 80 ~ 100 ml/mu for wheat and corn, 50% acetochlor EC 100 ~ 150 ml/mu for soybean, and 30 kg of water can be sprayed evenly in the field.

5. Scientific fertilization, the main methods to control the growth and lodging of soybeans are phosphorus and potassium fertilizers, and nitrogen fertilizers are applied as appropriate. The base fertilizer is 30 ~ 35 kg of calcium superphosphate and 8 ~ 10 kg of potassium sulfate. Depending on the growth of the field, 5 ~ 8kg of urea should be applied after corn harvest, and 3 ~ 4kg of urea can be applied to individual plots with poor growth after rain in flowering period. The fertilization level of wheat and corn is the same as that of "wheat/jade/potato" model.

When the main stem of soybean grows to 5 nodes (or branching stage), use 30 ~ 60mg/kg uniconazole (or Youkang) or180 ~ 250mg/kg paclobutrazol solution to spray 40 ~ 50kg water evenly on the stem and leaves. Spraying uniconazole with a concentration of 30-60mg/kg to 40-50kg of water on individual fields that are still flourishing at the initial flowering stage of soybean.

6. During the whole growth period, attention should be paid to the prevention and control of pests and diseases, timely harvesting, monitoring and prevention of root rot, virus diseases and aphids. Once symptoms appear, use drugs to prevent and control them in time. Plants with serious root rot and virus diseases should also be pulled out in time, taken out of the field and discarded. Use 50kg thiophanate methyl WP or 65% zineb WPl00g per mu to control root rot, and use 50% pirimicarb wettable powder 15 ~ 30g or 2.5% laifuling EC 15 ~ 20ml diluted water to control aphids, red spiders and other pests. The pest control of wheat and corn is the same as the "wheat/jade/potato" model.

The suitable harvest period of soybean is from yellow maturity to full maturity, and the suitable harvest period is that the pod skin is dry and hard, dried and threshed. Wheat and corn are harvested in time when they are ripe, which provides sufficient time and space resources for soybean growth.

(Communication: Ya 'an, College of Agriculture, Sichuan Agricultural University, 6250 14)