Response Of Hot Pepper Growth To Soil Constitution And Water Regimes

Soil constitution and water regimes directly affect the availability of soil water, which further influence plant growth and physiological processes. Hot pepper is one of the important economic crops in China. In this paper, the specific leaf area, photosynthesis, nutrient content, yield, fruit index and biomass of hot pepper at four kinds of soil constitution patterns and 3 kinds of water regimes were measured. The objective of this experiment was to reveal the physiological mechanism and soil physics mechanism of hot pepper in response to soil constitution patterns and water regimes, thus providing a scientific basis for soil improvement in sandy region. The main conclusion were given as follows:1. Through the flowering and fruiting stages, SLA was significantly higher in the lower sand treatment compared with other treatments. Net photosynthetic rate was increased by 35% and 27% higher in the soil and soil sand mixture treatments compared to lower soil treatment. Stomatal conductance change was soil>mixture>lower sand>lower soil. With the same trends stomatal conductance and transpiration rates. However stomatal conductance had only significant difference in pepper growth among the three water regime treatments. These results suggested that the effect of soil constitution patterns on net photosynthetic rate and transpiration rate were much greater than water regimes treatments. In addition, the effect of soil constitution on photosynthesis was related to the measuring periods and water regimes. Soil constitution had effects on the photosynthetic rate at the initial, mid and late stages, on the stomatal conductance and transpiration rate only at the initial stage. Under W1(75-90%FC) and W2(60-75%FC) regimes, the net photosynthetic rate, stomatal conductance and transpiration rate were higher in the soil and mixture treatments than lower soil treatment, but there was no significant difference between soil constitution treatments under W3(45-60%FC) condition. Meanwhile, the measuring periods obviously affected the growth of hot pepper. At flowering and fruiting stages, the specific leaf area was the highest at the end stage, photosynthetic and transpiration rates were the highest at the late stage; stomatal conductance was higher at initial, mid and late stages than at end stage.2. Pepper leaf nutrient content absorb characteristic was the total nitrogen content> total K content of> total phosphorus content. Through the flowering and fruiting stages, the soil constitution significantly affect the nutrient content of pepper leaves. TN and TK content in soil under the agreement were lower soil> lower sand> soil>mixture, TP content was lower sand> mixture> soil>lower soil. There had a strong significance in total nitrogen and total phosphorus among three water regimes, but no significance in total potassium among three water regimes. These results suggested that the effect of soil constitution patterns on leaf nutrition were much greater than water regimes treatments. In addition, the measuring periods obviously affected the nutrition of hot pepper. LNT was initial >mid>last>end, LKT was mid>last>end>initial, LPT was end>last>mid>initial. The results showed that total nitrogen and total potassium content of leaves with the growth progress downward trend, while the total phosphorus increasing. Based on net photosynthetic rate and nutrient content of correlation analysis, showed that the effect of soil structure and water on photosynthesis in part by adjusting the nutrient status to achieve.3. In different soil constitution, yield of pepper was soil>mixture>lower soil>lower sand, there has no significance in yield among lower soil and lower sand treatment. Pepper fruit index was lower soil>mixture>soil>lower sand. Leaves biomass and stem biomass in soil treatment were significantly higher than the lower sand, lower soil and mixture treatments. Plant height was soil>lower sand>mixture>lower soil. Total evaporation was soil>mixture>lower sand>lower soil. Under different water regimes, yield of pepper was W1>W2>W3. Leaf and stem biomass was W1>W2>W3. Total evaporation was W1>W2>W3. There had no significance in fruit index and plant height among three water regimes.Therefore, for the improvement of sandy soils in the semi-arid sand region, the lower sand and soil sand mixture soil constitution patterns and the soil moisture of 60%-75% field capacity were recommended.