钾肥用量对夏玉米干物质和钾素积累、分配及抗倒性的影响

Effects of potash application rates on the accumulation and distribution of dry matter and potassium nutrient and lodging resistance of maize

为合理施用钾肥,稳定夏玉米产量,减少倒伏,采用田间试验法,以河北省黑龙港低平原区冬小麦/夏玉米粮田为研究对象,研究钾肥用量对夏玉米产量及其构成因素、体内干物质和钾素积累与分配、茎秆抗倒性的影响。结果表明,增施钾肥促进干物质和钾素在植株体内各器官的运输和分配,植株干物质积累直到成熟期。成熟期,各施钾肥处理籽粒中干物重和钾素分别占整株的51.1%-57.0%和15.8%-20.7%,各处理籽粒干物质和钾积累量分别是灌浆期的1.33-1.61和0.70-0.97倍,整株干物质和钾积累量分别是灌浆期的0.98-1.15和0.75-1.00倍,说明钾和干物质在玉米体内的运输和分配不同步,在施用其他养分时应合理分期调控。施用钾肥增加玉米茎秆抗拉力、抗折力和穿刺强度,以K225处理最大,且茎秆抗拉力和抗折力均在灌浆期最强。同一植株随节位上升茎秆抗折力和穿刺强度下降,基部第3节作用最强。因此,钾肥用量225 kg·hm^-2时,不仅促进玉米体内干物质和钾素有效运输、积累和利用,增强其抗倒性,还可提高玉米产量,节约钾肥资源。

For reasonable potash application,stable summer maize yield and increasing lodging resistance,a field experiment was conducted in the rotation system of winter wheat and summer maize in the low plain area of Hebei province. Effects of potash application rates on the yield,accumulation and distribution of dry matter and potassium nutrient in different organs,and lodging resistance of stalk in maize were studied. The results showed that increasing potash application rates promoted the transportation and distribution of dry matter and potassium in different organs. Plant dry matter accumulated until maturity. At maturity,dry matter and potassium accumulation in grain to whole plant under different potassium treatments were 51.1%-57.0% and 15.8%-20.7%,respectively. Dry matter and potassium accumulation in grain at maturity were 1.33-1.61 and 0.70-0.97 times of those at grain-filling stage,while in the whole plant it were 0.98-1.15 and 0.75-1.00 times,respectively. These indicated that the process of potassium and dry matter transportation and distribution of maize was not synchronous. Other nutrients application should be regulated reasonably. Potash application increased the tensile strength,flexural strength and puncture strength of stalk,those of K225 were especially larger. The tensile and flexural strength of stalk was the strongest at grain-filling stage. Flexural and puncture strength decreased with the increase of stem section in the same plant,the third section from base had the strongest effect. Therefore,potash application rates of 225 kg·hm^-2 not only improved the dry matter and potassium transportation,accumulation and distribution in plant,strengthen the lodging resistance of stalk,but also increased the yield and saved the potassium resources.