| Abstrakt: |
Research was conducted (i) to determine the contribution of representative feedlots in semiarid southern Alberta to soil and water pollution, and (ii) to determine the effect of long‐term applications of manure on the N, P, and soluble salt content of cultivated soil under irrigation. The NO3‐N and available P content of the surface soil adjacent to the feedlots was generally greater than that of the soil away from the feedlots, but at depths greater than 150 cm the differences were usually small. Similarly, the concentration of NO3‐N and P in the ground water at 1‐ to 5‐m depths was usually increased only adjacent to the feedlot and, with minor exceptions, remained within “safe” limits most of the time. There was no evidence that a small lake or three permanent streams near feedlots were polluted by effluents from the feedlots. Manure applied annually for 40 years at a rate of 70 metric tons/ha did not cause an undesirable buildup of N, P, or soluble salts in the soil. |
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