Effects of sheep night penning on soil nitrogen and plant growth

摘要

Abstract A study on effects of sheep treading and excreta on soil and vegetation during night penning at 8 sheep nights m‐2 was carried out at Guizhou Weining Pasture Experimental Station from July to October 1998 with four treatments (UDT (urine+dung+treading), T (sheep treading), U (sheep urine), and D (sheep dung)) and an untreated control. Salix inamoena var. tetradenia was the dominant species in the natural vegetation. Sheep grazing and trampling removed almost all of the above‐ground natural vegetation, but did not significantly affect soil bulk density, penetration resistance, and air permeability. The peak concentrations of ammonium‐N (maximum 377 mg kg‐1) and nitrite‐N (maximum 56.1 mg kg‐1) in soil for UDT were potentially toxic to plants. The concentrations of ammonium‐N and nitrite‐N for U were 139 mg kg‐1 and 28.1 mg kg‐1, respectively, and were significantly (P < 0.05) higher than those of D and the control. Crude protein (N × 6.25) in the leaves of Salix inamoena var. tetradenia in treatme...