酸性红壤施石灰对甘蔗养分状况某些酶活性及生长的影响

研究结果表明．酸性红壤施适量石灰，能改善甘蔗的Ｎ、Ｐ、Ｋ养分状况，提高Ｃａ２＋－ＡＴＰ酶和中性转化酶活性，减缓甘蔗在伸长期Ｃａ２＋－ＡＴＰ酶活性降低的幅度，极显著地促进甘蔗生长。石灰施用量与甘蔗叶片Ｎ、Ｋ含量、Ｃａ２＋－ＡＴＰ酶活性及甘蔗株高里极显著或显著的二次函数曲线相关；与甘蔗叶片含Ｐ量、中性转化酶活性亦呈二次函数曲线相关，但相关性未达显著水平。研究结果还表明，施石灰量不同对甘蔗各生长时期株高的影响很大，施用量为１．２ｔ／ｈｍ２左右时，甘蔗前、中、后期的株高都极显著的高于对照，小于０．４ｔ／ｈｍ２或大于２．０ｔ／ｈｍ２时，甘蔗生长后期的株高与对照差异不显著．

EFFECTS OF LIME APPLICATION TO ACID RED SOIL ON NUTRIENT STATUS, ENZYME ACTIVITIES AND GROWTH OF SUGARCANE

The study showed that N, P and K status of sugarcane were improved,and Ca2+-ATPase activity and neutral invertase activity increased by lime application toacid red soil. Liming could also alleviate the decrease in Ca2+-ATPase activity at elongating stage, hence promoted sugarcane growth. The regulative effect of lime application on N, K contents, Ca2+-ATPase and sugarcane height resembled quadric curve.The same tendency was observed for neutral invertase activity and P content in sugarcane, but the correlation was not significant. It was also showed that appropiate application of lime (about 1. 2t/hm2) result in significantly higher yield than that of the checktreatment at tillering stage, early elongating stage and late elongating stage, when theamount of lime application was less than 0. 4t/hm2, or between 2. 0t/hm2 to 2. 4t/hm2,the yield of sugarcane did not significantly differ from that of the check treatment at lateelongating stage.