Micronutrient, magnesium and phosphorus effects on biomassand leaf tissue nutrient concentrations of field grown Leucaenaleucocephala

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• 作者：Khan ; S. H. ; Bingham ; R. L. ; Felker ; P.
• 关键词：forage ; leaf meal ; nitrogen fixing trees
• 刊名：Agroforestry Systems
• 出版年：1997
• 出版时间：1997
• 年：1997
• 卷：37
• 期：2
• 页码：157-173
• 全文大小：298 KB

文摘

To optimize biomass and crude protein (CP) production for leucaena(Leucaena leucocephala) in southern Texas, field trials were conducted withtreatment combinations of three levels of phosphorus (P) , two levels of Mgand two levels of soluble trace element mixture (STEM). The P was banded inthe soil while the Mg and micronutrient blend were applied to the foliage. Acombination of P (22 kg ha$^-1$), Mg and STEM fertilizerssignificantly increased biomass from 2555 kg ha$^-1$ to 3028 kgha$^-1$. This treatment was associated with an increase in leafCP from 27.9% to 31.0%. P fertilizer had no significant effecton leaf P, but significantly increased leaf nitrogen (N) and leaf copper(Cu). A foliar spray of Mg significantly increased leaf N, P, and Cu. Afoliar spray of a complete micronutrient blend increased leaf Cu. Biomassproduction was correlated positively (decreasing order) with leaf Cu, N, andMg and negatively with Zn. Leaf N was positively correlated with leaf P andcalcium. The critical tissue concentrations (CTC) (where 90% ofpredicted maximum leaf protein was obtained) were 0.18% and 4.49 mgkg$^-1$ for leaf P and Cu, respectively.