The yield response of a tall fescue/white clover sward to nitrogen rate and harvesting frequency
The yield response of a tall fescue/white clover sward to nitrogen rate and harvesting frequency
复制标题
高羊茅/白三叶草草地的产量对施氮量和收获频率的响应
DOI：
10.1111/j.1365-2494.1973.tb00735.x
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发表时间：
1973
期刊：
影响因子：
--
通讯作者：
J. Frame
中科院分区：
文献类型：
--
作者：
J. Frame
在S170高羊茅/S100白色三叶草草地上设置了8个施氮量（0 ~ 377 kg N/ha/a），每公顷施氮量为53.8 kg。在两年的每一年中，在3月至9月的24周生长期内，将年生长率分为8、6或4个相等的收获期，分别间隔3、4和6周。6周后，在10月进行了剩余收获。
根据数据拟合了牧草年产量与施氮量的关系曲线。总牧草DM响应108公斤N/公顷是小的，因为典型的白色三叶草产量氮率的相互作用，但几乎是线性的108至323公斤N/公顷在所有的收获频率。在较高的施氮水平下，频繁落叶比不频繁落叶的响应率下降得更少。高羊茅DM响应在0至323 kg N/ha范围内基本呈线性。第一年和第二年，总牧草的相对干物质产量为100：108：120和100：111：131，收获频率为3，4和6周。
总牧草CP响应曲线与DM相似，但继续上升更陡峭的最高氮率测试，377公斤N/公顷。高羊茅CP响应在0 ~ 377 kg N/ha范围内呈线性关系。收获频率对粗蛋白产量影响不显著。
第二年牧草干物质总产量比第一年减少14%。这种下降是由于白色三叶草的减少，主要是由于重复施氮的影响，也是伴生草和天气的辅助影响。
A series of eight fertilizer N rates, ranging from 0 to 377 kg N/ha per year, at increments of 53.8 kg N, was applied to a S170 tall fescue/SlOO white clover sward. The annual rates were split into 8, 6 or 4 equal dressings for harvests at intervals of 3, 4 and 6 weeks, respectively, over a 24-week growth period from March to September, in each of two years. Residual harvests were taken 6 weeks later in October.
Curves relating annual herbage yields to N rate were fitted to tbe data. Total herbage DM responses to 108 kg N/ha were small because of the typical white clover yield N rate interaction, but were almost linear from 108 to 323 kg N/ha at all harvesting frequencies. Tbe decline in rate of response at tbe bigher N application levels was less marked with frequent than with infrequent defoliation. Tall fescue DM responses were substantially linear from 0 to 323 kg N/ha. For the first and second years, relative DM yields of total herbage for harvesting frequencies of 3, 4 and 6 weeks were 100:108:120 and 100:111:131, respectively.
Total herbage CP response curves were similar to those for DM, but continued to rise more steeply to the highest N rate tested, 377 kg N/ha. Tall fescue CP responses were linear from 0 to 377 kg N/ha. Harvesting frequency did not markedly influence CP yields.
Total herbage DM yield was 14% less in the second year compared witb the first. The decline was due to a reduction in white clover, attributed mainly to the effect of repeated N applications, also the subsidiary effects of companion grass and weather.