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《Journal of plant nutrition》2013,36(3):683-690
Abstract A field experiment was conducted at Star City (legal location SW6‐45‐16‐W2); Saskatchewan, Canada from May 2000 to June 2000, to measure nitrogen (N) and phosphorus (P) supply rates from fertilizer bands to the seed‐row of canola crop. Ion exchange resin membrane probes (PRSTM) were used to measure N and P supply rates in four treatments [80 kg N ha?1 of urea as side‐row band, 80 kg N ha?1 of urea as mid‐row band, check/no N (side‐row)/P side‐row, check/no N (mid‐row)/seed placed P]. The treatments were arranged in a randomized complete block design with four replications. Two anion and cation exchange resin probes (PRSTM) were placed in each plot in the seed‐row immediately after seeding and fertilizing. The probes were allowed to remain in the field for 2 days and replaced with another set of probes every 4 days for a total of 14 days until canola emerged. Ammonium‐N, nitrate‐N and P supply rates were calculated based on the ion accumulated on the probes. Urea side‐row band treatments (fertilizer N 2.5 cm to side of every seed‐row) had significantly higher cumulative available N supply rates than mid‐row band placement in which fertilizer N was placed 10 cm from the seed‐row in between every second seed‐row. No significant differences were observed in P supply rates. The higher N rates (120 kg N ha?1) resulted in lower grain yield in side‐row banding than mid‐row banding possibly due to seedling damage. However, the earlier fluxes of N into the seed‐row observed with side‐row banding may be an advantage at lower N rates in N deficient soils. 相似文献
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在研究考察事物过程中,有时需要对个体从不同方面考察分析许多指标,以判定某总体中个体间的优劣。同分等概方法是把所有的考察指标都同分等概地分数化,以总分 相似文献
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‘豫黄瓜2号’为中晚熟一代杂种,适合春季小拱棚,春秋露地及秋延后栽培,高抗黄瓜枯萎病,霜霉病,白粉病,炭疽病,疫病,果实商品性好,产量可达75000kg/hm^2。 相似文献
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采用三因素五水平二次回归旋转设计,对杂交中稻旱育稀植的高产配套栽培技术进行了研究,配置出农艺措施效应的数学模型,并寻配出优化的农艺方案。 相似文献
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本文应用粒形指数对24个组合的亲本F_1和F_2代进行了研究,结果表明,不同粒形指数品种杂交的F_1代,其粒形指数介于双亲中值。F_2代粒形指数表现出中心对称的数量性状的分布特征,估算出粒形指数的广义遗传传力(h~2B%)为50—73.1%。 相似文献
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菏泽牡丹初花期的中长期预报模型 总被引:3,自引:0,他引:3
菏泽牡丹开花期短并且每年初花期离散度较大,这对办好菏泽国际牡丹花会造成严重困扰。本文通过牡丹初花期偏早、偏晚样本前期500hPa大气环流特征对比分析得出,牡丹初花期偏早和偏晚年份其前期环流有明显差异,因此,用1964-2006年牡丹花期序列对4月-翌年3月北半球500hPa月平均高度逐月进行相关分析,得出41个优势相关区,其中有4个是正相关区,其余为负相关区,正、负相关区出现有一定的时间性和区域性:正相关区出现在冬季太平洋和大西洋北部高纬地区,负相关区于上年4-5月在印度洋北部海区及赤道北太平洋海区出现并向北传播;再从优势相关区中筛选格点作为预报因子,建立一组牡丹花期中长期预报方程,最长预报时效超过150d。经几年试用效果较好。本方法对延长花卉花期预报时效有一定参考价值。 相似文献