氮肥施用方式對藺草產量與品質之影響

Abstract

於藺草整刈前之生育早期與整刈後之生育中、後期，每公頃各施用氮量（A）147kg及441kg，（B）84kg及346kg， （C）84kg及252kg，（D）84kg及301kg（其中49kg為大豆粕所含有）等4種施肥方式，分多次施用，以探討對藺草產量與品質之影響。發現慣行施肥方式A處理，於莖長、每叢莖數、乾草產量及有效莖率，分別為127.4cm、330支、18,400kg及70％，均有較佳表現，且比其他處理高，但經顯著性測定後，除有效莖率外，其餘性狀並未呈顯著差異，尤其與B處理相較差異甚微。實際收益比較，多施氮肥之A處理雖收益較高，惟其初期生育並未因於早期每公頃多施用63kg氮肥而比其他處理良好，且整刈後多施氮肥情況下，有紋枯病發生現象。因此，藺草氮肥施用方式，似應採用B處理之施用方式，於整刈前及整刈後，每公頃各施用氮肥84kg及346kg較適當。整刈後施用大豆粕之方式，於本試驗中無增產效應，似不宜採行。 The influences of amount and frequency of N fertilization on the yield quality of mat rush were studied with the aim at evaluating the adequacy of heavy application of N fertilizer in coventional cultural practice. The amount of N applied per hectare before and after tip-cutting for the four treatments were, respectively, 147 and 441 kg (treatment A), 84 and 346 kg (B) 84 and 252 kg (C), and 84 and 301 kg (D). Mean values of stem length, number of stem per hill, dry sraw yield and percentage of valuable stem (with length over 75cm) were highest for treatment A, the coventioal method of N fertilization (127.4cm, 330, 18,400kg/ha and 70%, respectively) as compared to the othe treatments. In other words, heavy N fertilization tended to restult in better agronomic performance. However, no significant difference existed among four treatments for most of the characters with the only exception of percentage of valuable stem. In terms of profit, treatment A was the highest among the four treatments. However, in this treatment the heavier application of N (63 kg/ha mor than the others) in the early stage did not enhance the growth, and sheath blight prevailed after tip-cutting due possibly to heaving N fertilization. Therefore, treatment B, i. e. 84 and 346 kg/ha of N applied before and after tip-cutting, respectively, was recommended. The application of soybean cake after tip-cutting did not increase the yield and exhibit any beneficial effect, and therefore was not recommended as a practical measure.