Effect of fertilizer nitrogen and biological nitrogen on the yield and quality of two types of forage.
1988
Rampersad I. | Ahmad N. | Griffith S. | Gabriel L.
The effects of chemically and biologically fixed nitrogen on the yield and quality of forage are compared. Quality is measured by the protein content of the forage produced. 3 levels of urea fertilizer (100 kg N/ha/yr, 200 kg N/ha/yr and 400 kg N/ha/yr) were applied to Tanner grass (Bracharia sp.) and compared with the introduction of Centrosema pubescens in the sward. Phosphorus (P) and potassium (K) were applied to some of the treatments and compared with treatments to which P and K were not applied over a 48-week interval. Levels of N fertilizer were applied in split applications at each harvest which occurred at 8-week intervals but P and K were applied at the onset of the experiment. The results indicate that there was no significant difference in yield between the 2 nitrogen sources. Also, increasing the rate of fertilizer N does not significantly alter the yield of the forage but introduction of the legume, C. pubescens, significantly increases the quality of the forage. P and K had no significant effect on the yield and protein content of the fertilized plots of grass/legume mixtures. They however increased the protein content of the legume-only treatments. The results of the experiment were affected by the physical characteristics of the soil. A gravel lens in the soil profile affected the water relations of the soil.
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