Effects Of Raising Chickens Under The Citrus Plantation In The Western Hills Of Sichuan On Soil Physical And Chemical Properties And Quality Of Fruit

In this paper, we chose the citrus orchard which was returned from cultivated land in west low mountain areas of Sichuan and studied the effect of chicken intensity (160 chickens per mu,80 chickens per mu,40 chickens per mu and non-chicken per mu) on physical and chemical properties of citrus soil and citrus qualities. The main results were as follows:(1) Soil capillary porosity, non-capillary porosity and total porosity of citrus orchard with chicken under it were significantly higher than those in non-chicken treatment. Compared with non-chicken treatment, soil bulk density(0～20 cm) of 160 chickens per mu,80 chickens per mu and 40 chickens per mu decreased 11.98%,9.69% and 2.67%, respectively, while in 20-40 cm layer they decreased 6.5%,2.5% and 1.3%,respectively, which indicated that raising chicken under forest could change soil physical properties. Soil natural moisture content, maximal water holding capacity, capillary moisture capacity and field capacity of different chicken intensities under different soil layer were all higher than those in non-chicken soils, and were all showed a tendency of 160/mu>80/mu> 40/mu>non-chicken. Soil water level in 0-20 cm layer was higher than that in 20-40cm layer which indicated a higher water holding, supply and retention capacity.(2) Soil structural granular index, aggregation state, aggregation rate and soil physical stability index in raising chicken treatment all increased and showed a tendency of increasing with the increase chicken intensity. The rate of soil structure deterioration, soil unstable aggregate index, soil dispersion rate, erosion coefficient and index of erodibility in raising chicken treatment all decreased and showed a tendency of decreasing with the increase of chicken intensity. The content of>0.5 mm aggregates and>0.25 mm water-stable aggregates were all increased with the increase of chicken intensity, which indicated that raising chicken under forest could enhance soil anti-erosion ability. The 160/mu treatment had the highest anti-erosion ability.(3) Soil organic matter, total nitrogen, alkaline hydrolylic nitrogen, available phosphorus and available potassium in raising chicken treatment were significantly higher than those in non-chicken treatment. Compared with the non-chicken treatment, soil organic matter in 0～20 cm layer of 160 chickens/mu,80 chickens/mu and 40 chickens/mu increased 66.34%,44.32% and 26.20%, respectively, and in 20-40 cm layer soil organic matter increased 61.33%,22.61% and 9.52%, respectively. Soil fertility significantly increased.(4) Fruit transverse diameter, vertical diameter, single fruit weight and fruit field per plant in raising chicken treatment were all higher than those in non-chicken treatment and all increased with the increase of chicken intensity. Compared with non-chicken treatment, single fruit weight of 160/mu,80/mu and 40/mu in citrus orchard increased 37.4%,25.6% and 17.8%, respectively, and fruit field per plant increased 32.30%,19.43% and 10.59%, respectively. The total soluble sugar content, total acid, protein, free amino acid and vitamin C in raising chicken treatment were all higher than those in non-chicken treatment and increased with the increase of chicken intensity, which indicated that raising chicken under forest could enhance the field and quality of citrus fruit.