Corn Silage Yield and Soil Chemical Properties as Affected by Cattle Feedlot Manure
1974
Mathers, A. C. | Stewart, B. A.
Cattle feedlot manure was applied at rates of 0-, 22-, 45-, 112-, and 224-metric tons/ha for 3 successive years to irrigated corn (Zea mays L.). Additional plots received 448- and 896-tons/ha for 2 years. Nitrate-nitrogen in the top 180 cm of soil was maintained at about 100 kg/ha by 22 tons/ha manure applied annually. However, manure rates of 45 tons/ha caused a small increase in soil nitrate-nitrogen and 112- and 224-tons/ha rates increased the nitrate-nitrogen remaining in the soil after three seasons to over 1,000 kg/ha. The highest concentration of the nitrate was between 30 and 60 cm, but nitrate accumulated to a depth of 360 cm. Organic matter, phosphorus, extractable potassium and sodium, and conductivity of a saturated paste extract increased in the top 30 cm of soil as the manure rate was increased. Applications of 224 tons/ha or more manure reduced corn silage (dry matter) yields. The optimum rate of manure application of corn silage production was 22 tons which supplied an average 300 kg/ha of nitrogen. Higher rates caused nitrate and salt accumulation in the soil and increased nitrate in the forage.
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