不同施肥水平和种植密度对青贮玉米农艺性状、产量及营养品质的影响

Effects of different fertilizer applications and planting densities on agronomic vieldandnutritional properties.quality of silage maize

为了了解施肥水平和种植密度对青贮玉米新品种“青玉517”农艺性状、产量及营养品质的影响,提升青贮玉米的产量,试验选取种植密度和氮、磷、钾施肥量4个主要影响因素进行4因素5水平正交试验,小区种植面积为18.0 m^(2)(3.0 m×6.0 m),行距为0.4 m,每个小区16行,株距根据种植密度确定。在籽粒乳线中期至蜡熟期之间(即乳线1/3~1/2之间)收获,在每个小区中间三行随机选取5株进行全株刈割,测量株高、茎粗、绿叶数、黄叶数、叶片持绿性、穗位高和单株鲜重,自然风干后测定单株干重,进行方差和极差分析。每个小区其余植株用机器粉碎收割,分别混合取样,送至中国科学院西北高原生物研究所分析测试中心检测粗蛋白、淀粉、中性洗涤纤维和酸性洗涤纤维含量,进行极差分析。结果表明:根据极差值确定种植密度对株高、茎粗、叶片持绿性、穗位高和单株干重影响最大,株高、穗位高、鲜重和干重随着种植密度的增加而逐渐增加,茎粗、叶片持绿性和淀粉含量随着种植密度的增加而逐渐下降;种植密度控制为6000~7000株/亩(1亩≈667 m^(2))时具有较高的产量和淀粉含量。钾肥对单株鲜重影响最大,随着钾肥施加水平的增加呈现先增加后下降趋势,施肥量在10.00 kg/亩时单株鲜重最大。根据极差值确定氮肥对粗蛋白、中性洗涤纤维和酸性洗涤纤维含量影响最大,随着氮肥施加水平的增加呈现逐渐上升趋势,施肥量控制在10.00~14.00 kg/亩时,具有较高的粗蛋白含量及较低的中性洗涤纤维和酸性洗涤纤维含量。磷肥对产量和营养品质的影响较小,为提升肥料利用率,控制在12.00~16.00 kg/亩为宜。说明不同种植密度和氮、磷、钾施肥量对“青玉517”的农艺性状、产量及营养品质具有明显影响,兼顾青贮玉米的产量和营养品质,控制种植密度为6000~7000株/亩,氮、磷和钾肥分别为10.00~14.00 kg/亩、12.00~16.00 kg/亩和7.50~10.00 kg/亩为宜。

In order to understand the effects of planting density and fertilizer application on the agronomic traits,yield,and nutritional quality of the new silage corn variety"Qingyu 517",and to improve the yield of silage maize,four main influencing factors of planting density and nitrogen,phosphorus and potassium fertilizer application were selected for a 4-factor,5-level orthogonal experiment.The planted area of the plot was 18.0 m^(2)(3.0 mx6.0 m),with a row spacing of 0.4 m.Each plot had 16 rows,and the plant spacing was determined according to different planting densities.The whole plants were harvested between the mid-milk line and the waxing stage(i.e.between 1/3 and 1/2 of the milky line).Five plants were randomly selected in the middle three rows for whole-plant mowing,then plant height,stem diameter,number of green leaves,number of yellow leaves,greenness,ear height,fresh weight per plant,and dry weight per plant were measured,and dry weight per plant was determined after natural air-drying,and analyzed for ANOVA and range analysis.Samples were taken from the rest of the plants in each plot after machine crushing and harvesting,and then sent to the Analysis and Testing Center of the Northwest Institute of Plateau Biology,Chinese Academy of Sciences for determination of crude protein,starch,neutral detergent fiber(NDF)and acid detergent fiber(ADF)contents,and analyzed for range analysis.The results showed that the planting density based on the range value had the strongest effect on plant height,stem diameter,greenness,ear height,and dry weight per plant.The plant height,spike height,fresh weight per plant and dry weight per plant increased gradually with the increase of planting density.The stem diameter,greenness,dry weight per plant,and starch content gradually decreased with increasing density.When the planting density was contrlled at 6000-7000 plants/667m?,it had a higher yield and starch content.K fertilization had the greatest impact on the fresh weight of a single plant,showing a trend of first increasing and then decreasing with the increase of potassium fertilizer application level.The maximum fresh weight per plant was obtained when the K fertilization application level was 10.00 kg/667 m^(2).The N fertilization had the greatest impact on the content of crude protein,NDF and ADF based on the extreme value,and the impact showed a gradual increase with increasing levels of N fertilization.When N fertilization was controlled at 10.00-14.00 kg/667 m^(2),higher crude protein content and lower content of NDF and ADF could be guaranteed.P fertilization had less effect on yield and quality,and it was more appropriate to control 12.00-16.00 kg/667 m^(2)in order to improve fertilization utilization.These results indicated that different planting densities and N,P and K fertilization amount had significant effects on agronomic characters,yield and quality of"Qingyu 517".Therefore,it was appropriate to balance the yield and nutritional quality of silage maize and to control the planting density between 6000-7000 plants/667 m^(2)and N,P and K fertilization between 10.00-14.00 kg/667 m^(2),12.00-16.00 kg/667 m^(2)and 7.50-10.00 kg/667 m^(2),respectively.