Study On The Yield Of Leguminosae Grazing In Winter Fallow Field And Its Influence On Biologic Function To Paddy Fields

The agronomy traits and yield performance of three legume forage, including horsebean, pea and Chinese milk vetch, planted in winter fallow fields, legume rotation effect on various environment factors, effect of different legume forage on growth of succession stubble rice, and the soil characters of rice paddy after harvested were studied. The result indicated that:1. Among the three legume forage, Chinese milk vetch showed the highest shoot density and LAI which is 5.9. Shoot density and LAI of horsebean was only next to that of Chinese milk vetch, which its LAI was 4.3. But the plant height of horsrbean was the highest. The fresh weight and dry weight of all legumes in maturing stage was higher than that in bear fruit phase. The fresh yield and dry yield of Chinese milk vetch in maturing stage was 137976.7 kg/hm2,17175.0 kg/hm2,respectively, horsebean 58929.3 kg/hm2,10621.5 kg/hm2,pea 26799.1 kg/hm2,6928.7 kg/hm2 Compared with winter fallow, in the winter, the soil in legume rotation field present higher night temperate and lower diurnal temperature variation, and this effect was most significant in Chinese milk vetch fields. The weed type and number in winter fallow field was greatly higher than that of legume rotation fields and weeds was more intensive in spring than in winter.2. Compared with winter fallow, planting legume could heighten grass yield of succession stubble rice. The highest fresh yield and dry yield presented at horse maturing and horse fructificationt, which increase production 16994.4 kg/hm2 and 3924.4 kg/hm2, respectively. Clipped in horsebean maturing treatment increased production 1255684.0 kg/hm2,3419.2 kg/hm2,, respectively. The highest grain yield presented at the treatment of clipped at Chinese milk vetch maturing, which increases production 1661.33 kg/hm2. The relative lower grain yield presented at the treatment of clipped at Chinese milk vetch maturing, which increases production 160.5kg/hm2, compared with that of winter fallow treatment.3. Planting legume in winter fallow field would improve soil moisture content,increase porosity, reduce bulk density. legume forage could be helpful in increasing organic carbon and microorganism carbon .At 0—5cm soil horizon, compared with the CK treatment, biological carbon in the Chinese milk vetch treatment increased by 32.5 %, then fallowing horsebean, 27.3 %, pea 18.5 %. Whereas at 10—20cm, Chinese milk vetch increased 22.5%,horsebean,17.2%,pea 10.1 %, respectively. 4. The soil moisture content of the four soil horison was ranked as: 15—20cm>10—15cm>5—10cm>0—5cm.The bulk density in 15—20cm was the highest. For the soil hardenered, as the soil was deeper.The CO₂ concentration that soil respiration released was nearly the same, but it varied more acutely at the CK. Its diurnal variation presented U profile. The CO2 concentration started to decrease at 6:00 in the morning. And it reached highest at 2:00 in the morning. At 14:00, there was a lower peak of CO2 released. The release of CH4 had a similar trend as CO2 .