Study On Screening Substrate Formula For Pepper In Soilless Culture

The aim of this study was to offer a theoretical and technical basis for the pepper substrate cultivation in protected culture. The pepper variety ?Longjiao No.3? was used as the test material and eight different substrate formulas were made by adding different volume ratios of fermented straw, sheep manure, cattle manure, mushroom residue, peat, vermiculite and river sand. The local traditional and commodity substrate were used as control to study the physical and chemical properties of different substrate formula and the effects on pepper plant growth, dry and fresh weight, leaf photosynthetic characters and gas exchange parameters, fruit yield and quality. The main findings are as follows:1. The growth of pepper in formula F(sheep manure:cotton-stalk:vermiculite:river sand:mushroom residue = 2:3.5:1:1:2.5), G(corn-stalk:cattle manure:turf: vermiculite:river sand = 2: 3.5:1:1:2.5), H(corn-stalk:cattle manure:turf:river sand=2:3.5:1:3.5), I(the substrate from N ingxia Zhongqing), J(corn-stalk: cattle manure: turf: vermiculite: river sand: mushroom residue=2:2.5:1:1:2.5:1) is better, the plant height and stem diameter are higher than formula A(the substrate from Shahe Substrate Factory). Compared with other formulas, formula C(sheep manure: wheat-stalk: cotton-stalk: river sand: mushroom residue=2:3.5:1:1:2.5) is worst, the plant height and stem diameter are significantly lower than other formulas.2. The amounts of dry matter accumulation in formula G, H, I, J are higher. Compared with formula A, the dry weight of plant over ground part of formula G, H, I, J is significantly higher, and increased by 53.6%, 22.8%, 50.7%, 24.9% respectively. The amounts of dry matter accumulation in formula C are lowest and significantly lower than other formulas.3. The photosynthetic capacity of formula F, G, H, I, J is higher, net photosynthetic rate is obviously higher than formula A, B(Sheep manure: Wheat-stalk:Cotton-stalk:river sand: mushroom residue = 1:2:2:2.5:2.5), C, D(Sheep manure: Wheat-stalk: Cotton-stalk: river sand: mushroom residue=3:1:1:3.5:1.5), E(Sheep manure:Wheat-stalk:Cotton-stalk:river sand: mushroom residue= 3:1: 1: 2.5:2.5). The photosynthetic capacity of formula B is 20.60 CO2?m-2?s-1and is lowest among the ten formulas.4. The pepper fruit soluble sugar and Vc content of formula G, H, J are higher than formula A, and fruit nitrate content is obviously lower than formula I. The fruit nitrate content of formula I is higher and its fruit quality is not good enough.5. The yield of formula G, H, I, J was 4034.86 kg/667m2, 3989.33 kg/667m2, 3797.91 kg/667m2, significantly higher than the formula A. Fruit number of single plant, yield of single plant and weight of single fruit are higher than others.6. According to principal component analysis, cluster analysis, the pepper fruit quality and the cost of substrate, G, H and J formulation substrate exhibited excellent physical and chemical properties, good growth and high net photosynthetic rate, good fruit quality and high yield, while the main raw material was from low cost agricultural waste and sand. Therefore, these three substrate formulations can be good for extend use in local areas.