栽培密度对无腺体棉饲草养分的影响

EFFECT OF PLANTING DENSITY ON NUTRIENT OF GLANDLESS COTTON FORAGE

无腺体棉饲草的密度试验表明，在６０万，９６万，１２０万，１５０万（株／ｈｍ￣２）四种密度间鲜草产量无明显差异，饲草的养分含量有明显不同。概略养分分析表明，粗蛋白、粗脂肪、总能随密度增高而上升，以１２０万（株／ｈｍ￣２）为最高，其后密度再增反而下降。粗纤维含量与密度成反比。矿质营养分析表明，常量元素中Ｋ含量，低密度栽培高于高密度；Ｃａ含量的增加则与密度成正比。微量元素Ｚｎ、Ｃｕ、Ｍｎ则与Ｃａ保持平衡增长趋势。氨基酸及维生素分析表明，即使在粗蛋白含量最低的６０万（株／ｈｍ￣２）密度中，限制性氨基酸──赖氨酸和甲硫氨酸的含量并不缺乏，必需氨基酸含量达到３１．５１％～３４．２９％。所测的ＶＡ、ＶＢ＿１、ＶＢ＿２中除ＶＡ量微外，余者均在正常范围。

The planting density test of glandless cotton forage proved that there were marked differences in nutrient content between the densities of 60, 96, 120,and 150 ten thousand plants/hm2,but the differences in fresh forage yield weren't marked. Proximate analyses showed that the contents of crude protein,crude fat and total energy increased with the density raised,reached the highest values at the density of 120 ten thousand plants/hm2 and dropped at the density of 150 ten thousand plants/hm2 awhile the content of raw fiber was inversely proportional to planting density. The analyses of mineral nutrient content showed that the element Ca increased parallelly with the trace elements Zn, Cu and Mn and proportionally to planting density and that the content of K was higher at low density than at high one. The amino acid analyses showed that limited amino acids (lysine and methonine)were enough even at the density of 60 ten thousand plants/hm2 when crude protein content was lowest and the rate of essential amino acids reached 31. 54 % - 34. 29 %. Vitamin A,B1 and B2 test showed that the contents of VitB1 and VitB2 were normal,only VitA was poor.