行距对马铃薯农艺性状及产量的影响

试验采用随机区组试验设计,大垄双行,整薯播种。在同一密度下对不同行距间的各指标进行比较及单因素方差分析。旨在为马铃薯生产和机械化作业提供理论依据。结果表明:在12株·m~(-2)和9株·m~(-2)的种植密度下,主茎数、结薯数、产量都是随行距的增加而呈现递减的变化趋势;在7.2株·m~(-2)的种植密度下,主茎数、结薯数、产量是随行距的增加而呈现"增-减-增"的变化趋势;同一密度下,淀粉含量随行距增加变化不明显,大部分维持在15%~16%之间。总体来看,同一密度下不同行距间对主茎数、结薯数、产量及淀粉含量的影响均差异不显著。     

日光温室越冬西葫芦高产栽培技术

选择抗病、耐低温、高产优质的品种,经过处理的种子在日光温室内建造苗床育苗,幼苗出土前,苗床气温白天保持28～30℃,夜间保持16～20℃。起垄定植,当幼苗三叶一心,苗龄25～30d时即可定植。定植后管理：浇一次大水、吊蔓、落蔓、肥水管理、温度控制、蘸花保果等等一系列措施。生长期要进行全面病虫害防治,以达到高产效果。     

调环酸钙25%悬浮剂对直播稻抗倒伏和产量性状的影响

为了研究新型植物生长调节剂调环酸钙在直播稻上的应用效果,本研究设计了调环酸钙25%悬浮剂在直播稻武运粳8号上的田间试验,用来了解其对直播稻的抗倒伏性状和产量性状的影响。试验结果表明:在直播稻武运粳8号的分蘖期使用调环酸钙25%悬浮剂12~15g/667m2均能够显著降低水稻的株高,缩短茎基部节间长度,提高水稻的抗倒伏能力,同时也能显著提高水稻产量。     

新疆甜菜丸粒化单粒种高密高产高糖栽培模式

在新疆适宜种植甜菜的生态区,通过选择甜菜丸粒化单粒种,在高密度种植条件下,依据不同栽培管理阶段特点采用合理的管理措施,以实现甜菜单产97.5～105.0t/hm2、含糖率15%以上的目标,从而构建甜菜丸粒化单粒种高密高产高糖栽培模式。     

围产期奶牛血钙影响因素及其与生产性能关系分析

本试验旨在探究围产期奶牛血钙浓度影响因素及其与生产性能的关系。于2018年7月20日—8月15日对北京地区36头围产期健康荷斯坦牛的血钙浓度进行测定,收集该牛场奶牛生产性能测定(DHI)报告,利用固定效应模型分析不同胎次、体况评分(BCS)、健康状况及血钙浓度变异度对血钙浓度的影响。结果表明:血钙浓度与产后天数存在显著的正向相关关系;经产牛的血钙浓度(1.40 mmol/L)极显著高于初产牛(1.31 mmol/L);不同BCS分组奶牛血钙浓度差异不显著;健康组的血钙浓度(1.41 mmol/L)显著高于患病组(1.30 mmol/L);血钙浓度变异度的大小影响奶牛的产奶量,初产奶牛低变异度组的产奶量(16.70 kg/d)显著高于中变异度组(9.75 kg/d)和高变异度组(5.63 kg/d)。本研究进一步揭示了围产期荷斯坦牛血钙浓度的变化规律以及其影响因素,为预防奶牛产后低血钙症的发生以及制定提高奶牛生产性能的饲养管理策略提供参考。     

Soil property differences among high‐ and average‐yielding soya bean areas in Arkansas,USA

Soya bean [Glycine max (L.) Merr] yields >6719 kg/ha (100 bu/ac) have only recently and infrequently been achieved. Quantifying soil property differences between high‐ and average‐yielding areas can help to further identify non‐plant‐related properties contributing to soya bean yield potential. The objective of this study was to evaluate the effects of region and soil depth on soil property differences between high‐ and average‐yielding areas. In each of the seven regions of the ‘Grow for the Green’ yield contest in Arkansas, prior to or just after harvest in 2014 and 2015, soil samples were collected from the top 20 cm of one contest high‐yield (HY ) area that was in close proximity to an average‐yield (AY ) area. Across all regions and both years, soya bean yields differed (P  <  0.05) between yield areas, averaging 4701 and 5498 kg/ha in AY and HY areas, respectively. Averaged across soil depth and years, numerous soil properties differed (P  <  0.05) between HY and AY areas within at least one of seven regions. Total soil C content was at least 20.2% greater in the HY than in the AY area in three of seven regions. Extractable soil P content was, on average, 19.4 kg/ha greater in HY than in AY areas in three of the seven regions. Results from this study have the potential to help producers better understand soil properties that contribute to or hinder achieving ultra‐high (>6719 kg/ha) soya bean yields.     

不同叶龄蘖、穗氮肥组合对粳稻产量及氮素利用的影响

以主茎叶片数不同的粳稻品种吉粳88 (14片)、沈农265 (15片)和沈农1401 (16片)为试材,采用大田筒栽方式,在总施氮量225kghm–2及轻简施肥(基肥、蘖肥、穗肥)模式基础上,设置基蘖肥∶穗肥6∶4和8∶2两种施肥比例,并分设不同源、库叶龄期施氮组合即不同叶龄蘖、穗肥精确施氮组合。分析了不同源库期氮肥运筹模式对水稻农艺性状、产量及氮素利用特性的影响。结果表明:(1)在有效穗数、分化颖花数、产量和氮素利用率方面,吉粳88、沈农265、沈农1401不同氮肥运筹下最佳蘖、穗肥叶龄组合均为6∶4显著高于8∶2。(2)不同氮肥运筹下,吉粳88在8叶(叶龄指数57.1%)、沈农265在9叶(叶龄指数60.0%)、沈农1401在10叶(叶龄指数62.5%)时,即叶龄指数在60%左右时,施用蘖肥效果最佳,最终穗数最多,对保蘖起主要作用;吉粳88在11叶(叶龄指数78.6%)、沈农265在12叶(叶龄指数80.0%)、沈农1401在13叶(叶龄指数81.3%)时,即叶龄指数在80%左右时,施用穗肥效果最佳,最终穗粒数最多,对促花起主要作用。(3)吉粳88-6∶4 (8, 11),沈农265-6∶4 (9, 12),沈农1401-6∶4 (10, 13) 3组处理,在产量、氮素积累量、氮素吸收利用率、农学利用率及偏生产力等方面,显著高于同品种不同叶龄蘖、穗氮肥组合中的其他处理。因此,适当延迟蘖肥施用叶龄期(叶龄指数60%左右)、提前穗肥施用叶龄期(叶龄指数80%左右)同时增加穗肥施用比例,既可以显著提高氮素积累量、氮素吸收利用率、农学利用率及偏生产力,又能显著促进成穗率的提高和颖花数的分化,达到保蘖促花的双重作用,实现优源、扩库、充实的目标,从而获得高产。     

How do timing,duration, and intensity of drought stress affect the agronomic performance of winter rye?

Winter rye (Secale cereale L.) will be especially affected by drought induced yield losses in Central and Eastern Europe in the future because it is predominantly cultivated on low-fertile soils with a poor water-holding capacity. In order to examine the performance of winter rye under different drought conditions, field experiments were carried out during the years 2011, 2012, and 2013 near Braunschweig, Germany. Two sets of genotypes were tested under severe, mild, pre-anthesis, and post-anthesis drought stress in rain-out shelters as well as under rainfed and well-watered conditions. The grain, straw, and total above ground biomass yields, harvest index, grain yield components, leaf area index (LAI), and phenological characteristics were examined, as well as phenotypic correlations between grain yield and further characteristics. Drought induced grain yield reduction ranged from 14 to 57%, while straw yield and harvest index were lesser affected by drought than the grain yield. Under drought conditions, fully ripe was reached up to twelve days earlier than under non water-limited conditions. Pre-anthesis drought mainly reduced spikes m⁻² and kernels spike⁻¹ while drought during grain filling reduced the 1000-kernel weight (TKW) only. The grain yield was positively associated with straw yield, spikes m⁻², and kernels spike⁻¹ under water limited conditions while the TWK was only positively associated with grain yield under drought during grain filling. Consequently, high pre-anthesis biomass as well as high numbers of spikes m⁻² and kernels spike⁻¹ are especially important for obtaining high grain yields under water-limited conditions. Focusing on these traits is, therefore, recommendable for developing drought tolerant rye genotypes.     

我国金银花产质量影响因素及轻简化施肥推荐

金银花是我国一种用途广泛的传统大宗中药材，年需求量大，影响其产量和质量的因素也较多。本文通过文献检索，从产地特点、品种特性、土壤性质和施肥管理措施及后期加工等方面对影响金银花产质量的主要因素进行了综述。并通过引入结构方程模型，对不同因素对金银花产量的相对影响程度进行了探索性分析，对于某一产地的具体品种，单株产量的主要影响因素是土壤有机质、pH和速效钾含量等土壤因素，和氮肥用量等施肥因素。在此基础上，针对当前施肥现状，借鉴根区施肥法，进行了以干花重为基准的施肥量推荐,并提出了将全年所需肥料一次性施于根区的轻简施肥法，旨在为金银花的轻简化高产高效优质栽培提供思路与参考。     

不同用量松土促根剂对冬小麦产量的影响

研究了Agri-Star松土促根剂在冬小麦上的合理用量,为该产品大面积推广提供依据.结果表明,在正常旋耕施肥(配方肥750 kg/hm2+旋耕12 cm,CK2)的基础上,获得最高产量的松土促根剂施用量为18.13 kg/hm2,最佳经济施用量为16.87 kg/hm2,施用松土促根剂13.5 kg/hm2处理较CK2平均增产26.18％.施Agri-Star松土促根剂是小麦生产上值得推广的新技术.