| This paper is to study the growth conditions of wheat and pepper and their micro-environment differences in different cropping patterns and different irrigation volume, through intercropping of wheat and pepper in different cropping patterns in the field. It is hoped to find the premium intercropping patterns and irrigation methods, aiming to increase the efficiency of water use and provide theoretical and practical basis for economical use of water resources in agriculture. The main findings of this paper are as follows:(1)In each model of intercropping of wheat and pepper, the water consumption of wheat increased with the wheat planting density. It was seen that the effect of different cropping patterns on wheat water-saving is impressive. The average daily water consumption of wheat in the growth period increased with the delayed growth period. During the symbiotic period of wheat and pepper, the daily water consumption reached up to the maximum in different planting patterns, and the overall trend of pepper daily water consumption was high - low - high - low. The water-saving effect of pepper in each model of planting was not obvious, but water-saving effect was remarkable with different treatment of water.(2)The overall plant height of wheat intercropping was more than the one of monoculture in each model, and it was showed some marginal effect; and during the early growth period of wheat the leaf area index of monoculture was higher than the one of monoculture, but in the period of tasselling and filling stage, because of the yellow leaf of wheat, wheat of monoculture was obviously premature, the leaf area index had the largest decline, and in the model of intercropping type 5-2 the high leaf area index could be maintained over a longer period.Intercropping of wheat and pepper can effectively change the field microclimate factors. Photosynthetic active radiation (PAR) of wheat intercropping system was significantly higher than the one of monoculture, and the higher photosynthetic active radiation could help to improve wheat production.Between the reserved lines in the intercropping of wheat and pepper, the wind speed at different height below the canopy increased with the height of measure point, in each model the wind speed declining scale at the height of 50cm and 25cm within the canopy increased with the space between narrowing, compared with the speed at the height of 75cm above the canopy.(3)Different planting patterns had different impact on the temperature, due to shading effect of winter wheat on the reserved role and the dynamic temperature changes during the symbiotic period. It was showed that between the lines of wheat and pepper, the ground temperature decreased with the reserved line narrowing. Intercropping of wheat could adjust the field ground temperature to meet temperature requirements at different growth stages of wheat. For pepper, during the symbiotic period of wheat and pepper the pepper seedling was small and in recover period. The shelter effect of wheat could effectively lower temperature between pepper rows, effectively prevent the pepper seedlings from sunburn, and also reduce water transpiration. It was conducive for seedling.(4)The transpiration rate of pepper was bimodal curve. The transpiration rate of full irrigation (CK) was significantly different from other transpiration rates, and in the flowering and fruit setting period the rate of T1, T4, T7 without irrigation was the smallest. The other transpiration rate was also difference. As a whole transpiration rate of each model has direct ratio of water irrigation. During the flowering and fruit setting stage the daily change of pepper photosynthetic rate indicated bimodal curve, and inadequate irrigation could improve the photosynthetic rate of pepper to some extent Change discipline of stomata conductance was consistent with photosynthesis rules. When the hydrous rate of soil could not meet the crop needs, the crop was bound to make some protective response The leaf stomata opening aperture of pepper with severe inadequate irrigation treatment was smaller than other treatments to meet their water need The control of stomata conductance in all treatments was the highest compared with CK.Water use efficiency of leaf was the highest at 8:00 in the morning, and the effect of water level on transpiration was greater than on photosynthesis. The water use efficiency for instantaneous processing varied widely, and the greater the water irrigation during flowering and fruit setting stage, the less water use efficiency was. During flowering and fruit setting stage T1, T4, T7's value of non-irrigation treatment was slightly higher than others, and the leaf water use efficiency with moderate inadequate water irrigation treatment was significantly better than the one with appropriate irrigation treatment. The water use efficiency of pepper monoculture for dealing with CK was the lowest. Low-scale irrigation could significantly increase water use efficiency, and a certain degree of water stress could prevent transpiration and thus reduce the void water, improve water use efficiency.(5)Through the analysis of relationship between irrigation and the various yield constitute,the result showed that the yield increased with water irrigation, and water consumption. Through the analysis of water use efficiency of production levels, it showed that water use efficiency of T2, T5, T8 are the largest of all models, which had 30mm irrigation during flowering and fruit setting period. Water use efficiency of T1, T4, T7 without irrigation treatments was similar to T3, T6, T9 with standard irrigation. Therefore, with conditions that the production level did not decrease dramatically, moderate water deficit can increase the water use efficiency. Although the water consumption of pepper monoculture was the largest one, the advantage of production also showed higher water use efficiency.(6)The curve of pepper stem flow rate was the wave-shaped curve, and the peak appeared around 14:00 at noon. The flux in the sunny day was significantly higher than the one in rainy and cloudy days.It was relatively stable at night. From about 8:00 am, the stem flow began to rise lightly at about 10am with conditions of sunny day. The stem flow of pepper seedlings would continue to strengthen, with the rise of sunlight and temperatures. The pepper seedlings were to conduct photosynthesis and transpiration, so the flow rate increased significantly than in the morning, and the maximum flow rate appeared around 14:00 in the afternoon. Because self-regulation of the plant, some stomata closed, transpiration reduced and stem flow rate also declined. In cloudy days, the active time of stem flow was later than the sunny days, and the peak should be significantly lower than sunny days; the change range of stem flow rate in the rainy days is not great. The trend of stem flow rate was similar at night, keeping minor runoff. While the stem flow rate change during the day was very different, and reached the peak; the one in sunny days was obviously more than cloudy and rainy days, and the one in cloudy days is greater than rainy days.(7)Considering the yield of winter wheat, water consumption of pepper, yield and water use efficiency, and net benefits of each model, it was recommended that in the Guanzhong Area intercropping of winter wheat and pepper was adopted with 5-2 cropping pattern. This pattern was planting 5 rows of wheat in the 1.2m band, reserved 45cm for planting pepper. It was reasonable to irrigate once for winter wheat (60mm irrigation in winter), and the yield could reach up to 6914.2kg·hm-2. In addition, because the pepper needed irrigation water when transplanting, irrigation water between the reserved lines would be helpful for the formation of wheat production. For pepper, during the flowering and fruit setting stage using moderate water-scarcity had certain impact on the yield, but water use efficiency could reach up to 6.69 kg·m-3 It played a very good effect of water-saving.
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