||Effect of Irrigation Frequency and Potasssium Fertilization Rate on Population Dry Matter Production and Grain Yield Formation of Winter Wheat
||Winter wheat,irrigation frequency,potassium fertilization,population quality,leaf area index,dry matter accumulation,grain yield formation
||为明确灌水次数和施钾量对河北平原节水栽培条件下高产冬小麦群体物质生产特性和产量形成的影响,分别于2006-2007和2007-2008年度在保定市和藁城市选用当地冬小麦推广品种(河农822、石新616)进行了灌水次数(0、1、2和3水,分别用W0、W1、W2和W3表示)和施钾量(K2O 0、112.5和225 kg/hm2,分别用K0、K1和K2表示)的两因素裂区试验.主要研究结果如下:
5、随灌水次数增加,小麦的水分生产效率下降.由于2007-2008年度小麦生育期间降水较多,导致小麦的耗水量增加,因此,两年度相同处理之间水分生产效率差异较大,2006-2007年度的小麦水分生产效率均高于2007-2008年度.随着灌水次数的增加两年度相同处理之间的差异逐渐变小,两年度W0K0处理之间差异最大,2006-2007年度高出2007-2008年度0.9 kg/ m3,相当于高27.8个百分点;W3K2处理差异最小,两年度相差0.1 kg/ m3,相当于3.1个百分点.总的来看,小麦的水分生产效率因产量和水分消耗而协调变化.灌2水的W2与灌3水的W3比较,W2的产量和水分生产效率均较W3高.
综合本研究各灌水次数和施钾量组合的产量及群体、个体指标分析,在河北平原节水高产栽培条件下,在保证底墒基础上全生育期灌拔节期和抽穗开花期2次水,在氮磷配合适宜条件下施用K2O 225 kg/hm2,可以基本满足目前高产、超高产对灌水次数和施钾量的基本需求,实现高产节水的双重效果.
||In order to clarify the effects of irrigation frequency and potassium fertilization on population dry matter production and grain yield formation, two field experiments was carried out during 2006-2007 in Gaocheng County and 2007-2008 in Baoding with locally commercial winter wheat cultivar Henong 822 and Shixin 616 respectively. The experiments during two winter wheat growing seasons was designed as split plot arrangement, with irrigation times as main plots (including 0, 1, 2 and 3 times, expressed as W0, W1, W2 and W3 respectively), and potassium application amounts as split plots (including K2O 0, 112.5 and 225 kg/ha respectively). The main results were summarized as follows:1. Irrigation frequency and potassium fertilization affected more or less the indexes of population quality, such as the population culm number, dry matter accumulation and LAI. The variances of population culm number before overwinter and at double ridge stage between the two growing seasons were statistically different, but the variances of population culm number between the two growing seasons were similar statistically. The population culms of W2 at mid-late phenostages were the highest among the four irrigation levels, with that of W3 slightly decreased. The dry matter accumulation increased with the increase of irrigation times and potassium amounts, with that of W0K0 always lowest, and that of W3K2 highest. The difference of dry matter accumulation among the four irrigation levels was different at various phenostages, with that of W0 always lower, and that of W3 higher than those of other levels statistically. Comparison among the three potassium levels, only the difference of booting spike between K0 and K1 was insignificant. The other growing stages were statistically different among the three potassium levels each other. The LAI increased with the increase of potassium amounts under the four irrigation levels at various growing stages between the two growing seasons. During 2006-2007, the LAI of different potassium levels were statistically different among the four irrigation levels each other. During 2007-2008, the indexes of LAI among the three potassium levels were similar statistically, only at some growing stages and irrigation levels were statistically.2. Irrigation frequency and potassium fertilization affected more or less the indexes of grain yield and yield components. During 2006-2007, the difference of grain yield and yield components among the four irrigation levels was different at various growing stages. Although the grain yield of W3 was higher than W2, the yield components of W3 were really not optimum, the difference of W3 and W2 was insignificant. During 2007-2008, The highest grain yield was obtained for W2, and higher than those of other levels statistically, as a result of the iteration of the three yield components. Comparison among the three potassium levels, only the difference of grains per spike between K0 and K1 was insignificant during 2006-2007. The other two yield components and grain yield were statistically different among the three potassium levels each other in the two growing seasons.3. Proper potassium fertilization can prolong the functional period of flag leaf, and increase chlorophyll content further. As compared with K0, chlorophyll content of K1 and K2 decreased more slowly, and remained at a high level 35 days after anthesis further. The interaction of irrigation frequency and potassium fertilization amounts on chlorophyll content of flag leaf was statistically significant. Photosynthetic rate of flag leaf increased with the increase of potassium application, under more times in irrigation. Under W0 condition, the photosynthetic rate of flag leaf in the three potassium levels all reached a peak at booting stage, and then decline after booting stage. Under W1 condition, the photosynthetic rate of K0 reached a peak at booting stage, but the photosynthetic rate of K1 and K2 reached a peak at anthesis. Under W2 and W3conditions, the photosynthetic rate of flag leaf in the three potassium levels all reached a peak at anthesis, and for a longer duration.4. The dynamics of potassium accumulation in the whole growing stages showed a single peak, with the largest amount at anthesis. On the phasic absorption of potassium, the highest uptake of potassium was at double ridge to stem elongation, about 43%. The interaction of irrigation frequency and potassium fertilization amounts on potassium absorption rate was statistically significant. During 2006-2007, under W0 and W1 conditions, the highest uptake of potassium on K0 and K1 was at double ridge to stem elongation, but the others were at stem elongation to anthesis. During 2007-2008, the highest uptake of potassium on all treatments were at stem elongation to anthesis.5. The water productive efficiency increased with the increase of irrigation times. As a result of the more precipitation during 2007-2008, the water consumption increased. Th