Effects Of Strip Intercropping Forage Cropping On Soil And Water Conservation And On Eco-Physiological Characteristics Of Crop Under Sloping Field

Southern arid areas in Ningxia, agricultural production depends on natural rainfall, effective rainfall shortage and uneven distribution of rainfall in time and space is a major factor constraining crop growth. Most of the farmland due to the role of heavy rainfall during the rainy season, causing heavy soil erosion and surface soil nutrient loss and soil degradation. Slope or ordinary wood hedgerow planting grass to reduce soil erosion has a significant effect. The intercropping technique with full use of environmental resources and increase crop production characteristics is widely used all over the country.And the slope of food crops and intercropping of alfalfa few bands, especially suitable for intercropping with the forage ratio that yield traits and characteristics of soil erosion has been reported rarely.Field experiments were conducted in southern Ningxia, Pengyang white Township of steep village arid point (106°32 ' 106°58' E, 35°4l ' 36°17' N) during 2007-2008. In the passed the field test, different slope (5°and 15°) on the millet/alfalfa and pearl millet/alfalfa under different intercropping treatment of production target population characteristics, soil erosion, were distinguished comparative analysis of the main results. The main results showed as follows:1. Characteristics of soil erosion of grain-grass strip intercropping planting in different slopes lands.1) Farmland to take food (millet or pearl millet) grass (alfalfa) strip intercropping planting can reduce soil erosion and agricultural soil N, P, K nutrient loss, in the 5°slopes, With a ratio of 4:2 and 2:4 intercropping patterns than with soil and water conservation effect is remarkable, compared with single-surface runoff by 30% ,to reduce surfacereduce sediment loss over 98%; in the 15°slopes, 4:4, 4:6 and 6:4 three intercropping treatment effect is remarkable, to deal with than a single 50% reduction of runoff, reduce sediment loss of 84%.2) Comparison of different rainfall, rainfall intensity greater the larger the surface runoff, runoff and soil N, P, K nutrient content increased, but the control effect of intercropping and soil treatment on soil N, P, K nutrient loss reduction rate is decreased . Forage test strip from the set point of view, its base to the end of the planting strip of alfalfa can effectively prevent sediment loss.3) Loss of soil nutrients prime means for the sediment loss and runoff loss, Comparison of per unit volume of sediment in the runoff of nutrients were significantly higher than the nutrient content in; total quantity, the total loss of nutrient runoff sediment loss was significantly greater than the total nutrients. In 14mm and 21mm rainfall, 4:2 and 2:4 intercrop intercropping treatment of 5°slopes than single treatments to reduce TN, AN, TP, AVP, TK and AVK loss of 62.3% 78.1% and 30.89% 52.16%; 4:4,4:6 and 6:4 intercrop treatment of 15°slopes less than TN, AN, TP, AVP, TK and AVK loss of 46.0% 65.4%. and 32.44% 65.5%.2. Effects of grain-grass strip intercropping planting on soil moisture and nutrients of field in different slopes lands.1) At the different slopes arid land, taking grain (millet or pearl millet) grass (alfalfa) strip intercropping system can improve the soil moisture content of food field, 5°slope farmland, the 2:4 intercropping cropping patterns is the most effective, 15°slopes field, the 4:4 ratio of arable is the best intercropping cropping patterns, soil moisture content of crops is higher 2.3 points and 1.08 percentage points than the control of an average single.2) Grain (millet or pearl millet) grass (alfalfa) of food crops with intercropping can increase water use efficiency (WUE), the 2:4 intercrop planting patterns of 5°slopes land crop water use efficiency increased to 1.92 kg/cm3 than single-disposed.The 4:4 intercropping of 15°slopes land crop water use efficiency increased 1.25 1.57 kg/m3 than single. 3) Grain grass strip intercropping cropping can increase the cultivation of food crops with the soil organic matter content and soil nitrogen and nitrogen content, 5°slopes with a 2:4 ratio of arable land to intercropping cultivation model best, 15°slopes farmland to 4:4 ratio of intercropping cropping patterns with the best of its food crops with soil organic matter, total nitrogen, nitrogen content increased with improved intercropping years.4) As compared with the single grain, grain grass strip intercropping plant model soil total K, available potassium and available phosphorus content was significantly increased . in the 5°slope farmland ,the 2:4 and 4:2 intercrop planting patterns is the best. in the 15°sloping land, the 4:4 ratio of intercropping on the plant model is the best.3. Effects of grain-grass strip intercropping planting on production and the growth and development of millet and panicum miliaceum in different slope lands.1) The grain yield of arid slope to grain (millet or pearl millet) grass (alfalfa) intercropping cropping pattern was significantly higher than food alone. In the 5°slopes, 2:4 intercropping forage yield optimal , compared with grain (millet or pearl millet) single planting, the yields of millet and pearl millet yield increased 23.88% and 21.44%; in the 15°slopes, 4:4,4:6 and 6:4 the three forage intercropping yield is better, yield millet and pearl millet high 13.22 15.72% and 10.31% 12.73% than food alone treatment, especially yield of 4:4 forage intercropping treatment is the most significant.2) Leaf area of grain grass intercropping planting patterns on food crops (millet and pearl millet) in height and growth period did not significantly affect, but significantly increased the crop green leaf area during growth period (heading-Mature ), promoting the accumulation of photosynthetic material. In the 5°slopes, 2:4 treatment of leaf area per plant increased 86.77 cm²/plant and 27.67 cm² /plant than the single treatment, and increased 77.39cm² /plant and 9.65 cm² /plant during maturity; in the 15°slopes, 4:4 intercropping millet and pearl millet processing single-leaf area increased 84.74 cm²/plant and 27.41cm² /plant than the singel planting , during maturity respectively increased 78.64cm²/plant and 12.21cm² /plant.3) Dry matter accumulation of grain grass intercropping cropping is not difference before ear stage ,but after ear, millet and pearl millet dry matter accumulation per plant of intercropping forage increased significantly. In the 5°slopes, 2:4 processing mode of the crop dry matter accumulation was significantly higher than the one for food processing, millet plant quality increase 15.75%, pearl millet plant quality for processing to increase 10.10%. In the 15°slopes, 4:4, 6:4 and 4:6 three treatments significantly increased the amount of dry matter accumulation than single plant , millet increased 25.47%, 13.48% and 10.79% and pearl millet increase 17.26%, 13.69% and 13.42% during maturity.4) Intercropping forage crops can be increased in stem and leaf sheath dry matter accumulation, and promote the heads of grain crops in the dry matter distribution. In the 5°slopes, millet and pearl millet dry matter accumulation of the intercropping treatment increased 0.43%⁹.21% and 9.55% 24.24% than single-handle; in 15°slopes, its separately increasing 7.5% 40.1% and 12.6% to 23.6%.5) Quality of root of forage intercropping cropping patterns effectively improved than food alone treatment. In the 5°slopes, millet of 2:4 forage intercropping processing mode number of roots per plant and quality were increased 1.4 twigs and 0.71g, pearl millet number of roots per plant and quality were increased 3.6 twigs and 0.32 g; in the 15°slopes, 4:4 intercrop treatment millet number of roots per plant and quality were increased 5.3 twigs and 0.55 g, pearl millet were increased 3.6 twigs and 0.32 g.4. Effects of grain-grass strip intercropping planting on index of the physiological ecology of millet and panicum miliaceum in different slopes lands.1) In the arid slopes of different slope, the millet and pearl millet in the photosynthetic rate of change was "M"-type bimodal curve, in the afternoon between 2:00 -4:00 "midday depression". Transpiration rate and stomatal conductance and photosynthetic rate on changes in the performance of the same changes, changes in intercellular CO₂ concentration of the photosynthetic rate changes and not related, present trend of high to low. 2) Compared with the monoculture of grain, forage crop intercropping treatment can significantly increase the transpiration rate and stomatal conductance and net photosynthetic rate. In 5°slopes, 2:4 intercropping millet average net photosynthetic rate was increased 1.46μmol·m^-2·s^-1 than the one for handling, pearl millet leaf net photosynthetic rate than the one for the average treatment increased 2.41μmol·m^-2·s^-1; 15°slopes, 4:4 forage most obvious effect of intercropping millet average net photosynthetic rate than the food alone for treatment increased 3.17μmol·m-2·s -1 and pearl millet increase 1.68μmol·m^-2·s^-1.3) Millet and pearl millet in the LAI from the beginning of jointing was low - high - low trend, the maximum in ear stage; the CGR is bigger during the jointing-heading and heading to filling stage and the CGR of emergence is low and dry matter accumulation slow. Millet leaf area and time to obtain the highest net assimilation time is jointing-booting and emergence- jointing stage, NAR began to decline after the booting and the lowest in filling- maturity. NAR values of pearl millet were higher in three stage of the emergence-jointing and jointing-heading and heading-filling, during the filling-maturity was significantly lower.4) The forage intercropping millet and panicum miliaceum population characteristics indicators were increased. Leaf area index, crop growth rate and net assimilation rate improved significantly during different growth stages. In the 5°slopes, 2:4 forage intercropping patterns was most obvious, millet LAI values was larger than the monoculture of 20.05%, 25.25% and 50.22%, pearl millet increased 30.51%, 20.10% and 33.69% during in grain filling and maturity. During the jointing-heading and heading-filling stage, millet CGR values were increased 46.90% and 54.81% and NAR were increased 26.67% and 50.0% than single planting, pearl millet of the CGR values were dealing with 36.54% respectively and 16.05%, NAR were increased 36.36% and 20.0% than handling. In the 15°slopes, 4:4 forage intercropping patterns was most obvious. During grain filling and maturity, millet LAI values was larger 17.75%, 25.24% and 45.46% than the monoculture, pearl millet increased 31.96%, 31.07% and 46.29%. During the jointing-heading and heading-filling stage, millet CGR values were increased 46.90% and 74.05% than sigle planting, NAR were increased 36.54% and 42.86% than single; pearl millet of the CGR values were more 25.0% and 45.45%, NAR were increased more 36.36% and 40.0% than single planting.