Isotopic and Nonisotopic Estimations of Fertilizer Nitrogen Uptake by Sudangrass in Field Experiments1
Isotopic and Nonisotopic Estimations of Fertilizer Nitrogen Uptake by Sudangrass in Field Experiments1
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田间实验中苏丹草吸收肥料氮的同位素和非同位素估算1
DOI：
10.2136/sssaj1974.03615995003800010033x
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发表时间：
1974
期刊：
影响因子：
--
通讯作者：
L. T. Kurtz
中科院分区：
文献类型：
--
作者：
R. L. Westerman;L. T. Kurtz
采用差值法估算大田试验作物地上部分氮肥回收率；作物全氮对施氮量的线性回归/sup 15/N同位素示踪法；以及标记肥料氮素吸收率与标记肥料氮素吸收率的线性回归。为了评估同位素的使用，这四种方法应用于先前报道的2 /sup 15/N标记肥料（尿素和草酰胺）在0、56、112和188 kg N/ha速率下的实验数据。试验作物为Sudax （SX11）高粱-苏丹草杂交种（高粱苏丹），在种植季节每隔大约30天收获一次。与同位素示踪法相比，差异法在1986年和1987年分别高估了苏丹草中尿素和草酰胺氮的回收率，分别为35%和31%和23%和35%。同样，1988年和1987年，作物全氮对施氮率的线性回归对尿素和草酰胺氮的回收率分别高估了32%和17%，而对施氮率的线性回归对肥料氮的回收率分别高估了17%和21%。同位素标记肥料在许多土壤学试验中几乎是估算Nmore»回收率所必需的。«少
Recoveries of fertilizer N in above-ground portions of crops grown in field experiments were estimated by: the difference method; linear regression of total N in crops on rates of applied N; /sup 15/N isotopic tracer method; and linear regression of labeled fertilizer N uptake on rates of labeled fertilizer N. In order to evaluate the use of the isotope, these four methods were applied to data from prsviously reported experiments that involved two /sup 15/N-labeled fertllizers (urea and oxamide) at rates of 0, 56, 112, and 188 kg N/ha. The test crop was Sudax (SX11) sorghumsudangrass hybrid (Sorghum sudanense) and harvests were made at approximately 30-day intervals during the cropping seasons. The difference method overestimated recovery of urea and oxamide nitrogen in sudangrass 35 and 31%, respectively, in 1986 and 23 and 35% in 1987 when compared to the isotopic tracer methed. Similarly, linear regression of total N in crops on rates of N overestimated recoveries of urea and oxamide nitrogen 32 and 17%, respectively, in 1988 and 17 and 21% in 1987 when compared to linear regressions of fertilizer N in crops on rates of /sup 15/N labeled nitrogen. Isotopically- labeled fertilizers are almost a necessity for estimating Nmore » recovery in many dgronomic experiments.« less