Research Of Sowing Amount And Harvest Time Of Forage Rape After Spring Wheat Harvesting In Irrigation Area Of Ningxia

The area of traditional wheat-corn relay intercropping have dwindled in the irrigation area of Ningxia, and wheat is mainly planted with monoculture. "Single-season is sufficient, while two seasons are insufficient in time every year" becomes a most conspicuous problem. The model of multiple cropping of wheat stubble is not stable and it has a low economic results. Aiming at the problem, this paper puts forward a key technology of multi-cropping forage after wheat for solving the problem. The authors used the Huayouza62 as experimental to conduct a field trial, and the seeding quantity and harvest date were taken as the major test factors. The biological character, nutrient absorption, crude fiber content, crude ash content, content of crude fat, crude protein content, content of calcium, Fresh grass yield, Hay yield were measured to makes economic effects analysis in order to find the efficient model of Multi-cropping forage after Wheat. And then we can provide theoretical and technology support for increasing resource utilization rate of soil, fertilizer and water. The results as follows:1. Forage growth was "S" type change trend with the growth period. The whole growth period of forage rape fresh matter and dry matter accumulation increased with the growth period of promoting a "s" curve accorded with logistic growth equation. The growth prophase growth is faster than late growth, appropriate low density planting can increase plant fresh matter and dry matter accumulation and forage rape fresh matter and dry matter accumulation were gradually reduced with increasing seeding rate, in each treatment. The fresh and dry matter accumulation of 400 g/667m2 was the highest, respectively, up to 393.93g/plant,34.39g/plant. The fresh and dry matter accumulation of 1000 g/667m2 treatment was the lowest, which was 177.55g/plant and 16.18g/plant respectively.2. Nitrogen, phosphorus and potassium and their accumulation in forage plants varied with the sowing date and growth stage. The accumulation of N, P2O5 and K2O in forage increased with the growth of fertility, and decreased with the increase of seeding rate. The content of nitrogen, phosphorus and potassium in different growth stages were different, but the amount of N, P and K decreased with the increase of sowing amount. In the whole growth period, the total nitrogen content of forage within the scope of 2.29%-4.66% was first increased and then decreased with the trend, total nitrogen content with seeding rate decreases; total phosphorus content in the range of 0.51%-1.67% along with the duration of the gradually decreased, total phosphorus content with increasing seeding rate decreases; total potassium content within the range of 2.83%-6.56% with growth stage propulsion was first increased and then decreased, total potassium content decreased gradually with increasing seeding rate. The correlation analysis showed that N accumulation and plant height had great effect on the fresh weight of plant, and increase the value of these two indexes was beneficial to increase the yield of forage rape.3. The quality indexes of forage rape varied with the sowing date and harvest time. During the whole growth period, the crude ash, crude fat and calcium content of forage rape decreased gradually with the development of fertility, the content of crude protein increased first and then decreased, and the crude fiber increased gradually with the growth period. The crude ash, crude fat, crude protein and calcium content of forage rape with different sowing amount decreased with the increasing of three times, while the crude fiber content increased with the harvest time. In the harvest period, the crude ash, crude protein, crude fat and calcium content of forage rape decreased with the increase of the seeding rate, and the content increased with the increase of the seeding rate. The changes of contents of crude protein, crude protein, crude fat, crude fiber and calcium content were 14.00%～14.85%,15.32%～ 17.46%,10.41%～12.35%,9.04%～10.03%,2.08%～2.48% and, respectively, with the three harvest period of different crude ash, crude protein, crude fat, crude fiber and calcium content.4. Forage rape yield increases first and then decreased with increasing seeding rate, when the sowing amount is less than 700 g/667m2 and yield with the seeding rate increased, greater than 700 g/667m2 and yield decreased; rape yield gradually increased with the harvest time of, to harvest period Ⅲ (September 18th) yield was the highest (4035.35 kg/667m2), the harvest time Ⅰ and harvest time Ⅱ yield 11.13%,2.83%. The suitable sowing amount of forage rape was about 700 g/667m2, and the highest yield was about in September 18th.