The red edge characteristics of summer maize at different nitrogen levels and their relationships with the dry matter accumulation above ground and chlorophyll content were analyzed.Meanwhile,five function pattern of the chlorophyll content and drymatter accumulation modeling based on the red edge of summer maize was established.The results showed that there wasdouble peakphenomenon for the red edge of canopy spectra in the summer maize,reaching its highest in the flowering period.There wasred shiftphenomenon for the position of red edge along with the growth period.While after the flowering period,presentingblue shift.There was a red edge platform phenomenon for the position of red edge between the flowering period and filling period in nitrogen treatment.Along with the increase of nitrogen level,the position of red edge changed a little,but the slope of red edge appeared to be an increasing trend.The correlation between the position of red edge and chlorophyll content,chlorophyll a content,chlorophyll b content,carotenoid content was significant.Meanwhile,the significant correlation between the slope of red edge and the drymatter accumulation and chlorophyll b content was also shown.The results showed that the binomial function regression model was better than the model of liner,the power function,index and logarithm function,and it had good prediction ability.

以保绿性品种金海5号和非保绿性品种浚单20为试验材料,研究氮肥调控对不同保绿性超高产夏玉米产量及光合特性的影响.结果表明:(1)保绿性玉米较非保绿性玉米花后叶面积指数大,叶面积持续期长,群体光合势大,是增产的主要因素；(2)整个籽粒灌浆期间,氮肥调控对不同保绿性玉米均正向增加灌浆速率最大时的生长量和最大灌浆速率,有效增加籽粒灌浆积累量(籽粒干重)；(3)非保绿性玉米干物质积累特性变化、叶面积指数变化、穗位叶净光合速率变化、籽粒灌浆积累量变化受氮肥调控作用比保绿性玉米显著；(4)通过大田试验并结合数学计算,建议推广种植保绿性玉米,达到13 382.11 kg/hm2超高产量,应施纯N271.56 kg/hm2.

玉米在适宜种植密度基础上再增加密度,其产量的增减除与品种本身遗传特性有关外,很大程度上还取决于当年的气候状况,若当年气温适宜,光照充足,雨量充沛,适当增加密度可能会提高产量,反之会降低单位面积产量.

An experiment was conducted to research the morbidity of maize rough dwarf disease in different planting methods and study the effects of maize rough dwarf disease on the plant physiological characteristics in four ecological regions of Shandong province.The results showed that it could decrease morbidity of maize rough dwarf disease efficiently to postpone seedling stage and adopt direct seeding.The morbidity decreased 84.1% on the average in four ecological regions.With different serious degree,plant dry matter weights were decreased significantly,and grain yield per plant were decreased by 66.8% and 100%.The content of chlorophyll a,chlorophyll b and carotenoid,especially which of chlorophyll a and b,were decreased significantly after being caught the virus disease,and the content of chlorophyll a and chlorophyll b in the leaves of the four cultivars decreased by 13.4%,58.4%,62.5% and 27.8%,and 17.4%,72.2%,77.4% and 41.4%.Leaf area,plant height and stem diameter were decreased significantly and there was no significant difference in specific leaf weight.

Taking high-yielding summer maize cultivars Zhengdan 958 (ZD 958) and Denghai 661 (DH 661) as test materials, this paper studied the effects of different planting density (22500, 45000, 67500, 90000, and 112500 plant x hm(-2)) on the grain yield and source-sink characteristics of the cultivars in four regions, i.e., Shandong Agricultural University, Wenkou, Yanzhou, and Laizhou. At the planting density 112500 plant x hm(-2), the grain yield and the biomass of the cultivars were the highest, being 19132 and 36965 kg x hm(-2), respectively. Comparing with those at the planting densities 22500 and 67500 plant x hm(-2), the grain yield at the planting density 112500 plant x hm(-2) was increased by 72% and 48%, and the biomass was increased by 152% and 112%, respectively. With the increase of planting density, the leaf area index (LAI) increased significantly, while the leaf area per plant (LA), the maximum number of filaments, the grains per ear, and the 1000-grain weight all decreased. The harvest index and the grain-leaf ratio decreased with increasing planting density, but no significant change was observed when the planting density was higher than 67500 plant x hm(-2), suggesting that at higher planting densities, summer maize could improve their grain yield via increasing population sink.

本文通过分析山东省村级财务管理的四种模式,思考和探索适合农村实际发展情况的村级财务管理模式。