Abstract |
The pollutional potential of the surface runoff water was based upon the following factors: nitrate nitrogen, sodium, potassium, and electrical conductance. Based upon these four factors, the study indicates that high manure applications to cultivated soils will cause pollution of surface runoff water only during the first fifteen minutes of the first runoff event. Although 'polluted', the concentration of pollutants in this runoff water is below the limits set for irrigation water. Hence, all runoff should be re-cycled for irrigation uses only. After one year of heavy manure application, the underground water (static level at 47 feet below grade) retains potable quality. Indications are that repeated annual application of heavy rates of manure on land will lead to deterioration of the physical properties of soil, owing to the large amounts of sodium and potassium innure. Also, feeding large quantities of sodium and potassium beyond the minimum requirement for the animals should be avoided. Irrigation techniques indicate: the initial intake of water into the soil increases as higher manure loadings are applied, the basic intake rate is higher on areas plowed 8 inches deep, and the basic intake rate on any specific manure loaded area increases with time elapsed from date of manure application. (Author) |