Effects of compost application and decreased amounts of fertilizer on the quality and yield of carrot
2009
Yokoyama, A.(Miyazaki-ken. Agricultural Research Inst. (Japan)) | Nishihara, M. | Ueda, S. | Kawasaki, Y.
A study was conducted on the decreased amounts of nitrate nitrogen applied to carrot. 1. Plant height and root length varied substantially between years. Leaf weight tended to decrease when no compost was applied. A three-year comparison showed significant differences in root weight depending on compost application. 2. The nitrogen concentration of leaf did not vary between treatment groups but that of root varied significantly between control group and no nitrogen group. 3. Nitrogen concentration gradually decreased in leaf to 2.5-3.0% at harvest. It sharply decreased in root initially and was 1.0-1.3% at harvest. 4. The amount of potassium absorption was found to vary significantly depending on compost application. 5. There was no fixed tendency in the nitrate nitrogen concentration of either leaf or root at harvest. 6. A high positive correlation existed in nitrate ion concentration between leaf and root. Nitrate ion concentration decreased substantially in leaf at the initial stage of growth. Nitrate ion concentration gradually decreased in root and was 300 mg/L or lower at harvest. 7. Nitrate ion concentration in leaf at harvest was in a decreasing order of compost application for four years compost application for one year no compost application. No difference was found in the nitrate ion concentration of root at harvest by the number of compost application years.
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