不同栽培模式旱作春玉米农田土壤水分时空动态和产量效应

于2012年和2013年连续两年进行田间定位试验,研究在全膜双垄沟覆盖条件下不同施肥和开花期揭膜处理对春玉米农田土壤水分时空变化特征、土壤含水量和水分利用效率的影响。试验设农户模式(施N 200kg·hm-2,半膜,CK)、高产栽培(施N 380 kg·hm-2,T1)、高产高效栽培(施N 225 kg·hm-2+有机肥,T2)、再高产高效栽培(施N 225 kg·hm-2+有机肥+开花期揭膜,T3)等4个处理,以先玉335为供试玉米品种,分别在玉米各个关键生育期测定土壤含水量,收获测定实际产量。结果表明,T2、T3处理在生育前期、中期不仅能够高效利用浅层(0~100 cm)土壤水分,而且有利于促使深层(100~200 cm)土壤水分向上迁移,为玉米生育后期雨季充分蓄纳降雨腾出库容;从播前到收获0~200 cm土壤贮水量均降低,收获时各处理贮水量依次为CKT1T2T3,差值均小于5 cm,没有显著差异。土壤含水量在0~60 cm土层变化幅度大,而深层(160~200 cm)比较稳定。四种处理间耗水量、产量和水分利用效率存在不同差异,表现为T3T2T1CK。尤其2013年四个处理产量和水分利用效率均达到显著水平,T1、T2、T3产量分别比CK高27.4%、34.8%、42.4%,CK处理水分利用效率比T1、T2、T3分别低21.7%、29.9%、23.7%。高产高效栽培,特别是开花期揭膜的再高产高效栽培模式,在玉米整个生育期不仅没有导致土壤剖面土壤水分显著降低,而且可显著提高籽粒产量和水分利用效率,是该地区值得推广的旱作春玉米栽培模式。     

小麦抗旱性生理生化机制及QTL研究进展

根据现有文献资料,综述了小麦抗旱性的鉴定方法和抗旱小麦的外部形态特征,并对小麦胚芽鞘长度、叶绿素含量、叶绿素荧光动力、渗透调节、水分利用效率、碳稳定同位素等抗旱性鉴定评价指标和抗旱性产量评价方法、干旱胁迫下特异蛋白代谢及抗旱性状的数量性状位点(QTL)等方面的研究进展进行总结,对目前小麦抗旱性研究存在的问题和发展趋势进行了探讨。认为,抗旱性研究仍是农业研究的热点领域,但在不同的生态区要有所侧重,同时选择与产量相关性高的指标进行深入研究;应加强干旱胁迫下根系形态结构及生理代谢的研究;随着分子生物学研究的不断发展,抗旱性研究也应从分子水平阐明干旱胁迫引起作物生理生化变化的原因,并借助基因工程手段进行抗旱基因重组,进而创制、培育综合性状优良的抗旱小麦品种。     

Water and nitrogen balance of sweet sorghum (Sorghum bicolor moench (L.)) cv. Keller under semi-arid conditions

In the framework of the E.U. project Fair CT 96-1913 “Environmental studies on sweet and fibre sorghum, sustainable crops for biomass and energy”, a research has been carried out with the aim to study the water and nitrogen balance and determine the critical N dilution curve of sweet sorghum cv. Keller. A field experiment was performed, where three irrigation treatments (I₀ = dry control, I₅₀ = 50% ETm restoration, I₁₀₀ = 100% ETm restoration) and four nitrogen fertilization levels (N₀ = no nitrogen control, N₆₀ = 60 kg ha⁻¹, N₁₂₀ = 120 kg ha⁻¹; N₁₈₀ = 180 kg ha⁻¹) were studied. The final yield was significantly affected by the amount of water distributed but not by the nitrogen level. The treatments watered up to crop establishment (I₀) produced, in the average, 7.5 t ha⁻¹ of dry matter, against 21.1 and 27.1 t ha⁻¹ of I₅₀ and I₁₀₀, respectively. The crop determined a great reduction in nitrate concentration of soil water, irrespective of nitrogen supplied. The variation between N output and input (Δ) was negative in N₀, N₆₀ and N₁₂₀ and positive in N₁₈₀. The critical value of nitrogen uptake change in relation to the water availability. The amount of nitrogen supplied did not determine significant differences upon WUE. The crop seems to have a great potentiality in Mediterranean environment in terms of yield production.     

Study on Water-Preserving Effects of Mulching for Dryland Winter Wheat in Loess Tableland

Focused on the rainfall characteristics and the reality of agricultural production in the loess ta-bleland, and based on previous results, new patterns for dryland winter wheat production, in which the em-phasis was put on the film mulch with obvious water-preserving advantage, were designed to make effective useof rainfall. The results showed that the technique of the double mulch of film plus straw in summer fallow pe-riod can collect the rainfall in this period to the utmost extent and over 73.2 % of it can be stored in the soil,which is 108.4 mm more than that of conventional tillage. Furthermore, it can not only preserve water storedin soil in summer fallow, but also collect the rainfall in the growth period as much as possible by using thetechnique of making ridges plus film mulching and furrow sowing. So the patterns, which can greatly increaseboth the soil moisture and wheat yield, are the best choice for making full utilization of the rainfall and achie-ving a high and stable yield in the dryland wheat production of the loess tableland.     

宁南山区主要粮食作物生产力和水分利用的研究

在3个有代表性的气候年份（1981-1983年）,6种地区类型,两种肥力条件下对宁夏南部山区主要粮食作物：小麦、糜子和谷子的生产力和水分利用进行了研究。结果表明：该地区当前粮食作物平均生产水平为亩产75公斤,蒸腾蒸发量（ET）280mm,水分利用率（WUE）0.27,作物对土壤储水利用程度为53.3%。提高土壤肥力可显著提高作物对土壤水分的利用效率和利用程度。根据试验资料,预测了该地区粮食作物的生产潜力,讨论了3种作物对气候、土地的适应能力及合理布局。     

旱地全膜双垄沟播玉米高效用水机制研究

通过田间试验对半干旱区不同栽培方式下玉米土壤水分分布及水分利用效率的研究,探明了全膜双垄沟播玉米农田高效用水的机制。结果表明:全膜双垄沟播栽培不同位置大垄、垄沟、小垄土壤平均含水量在0~60 cm土层内差异显著(P0.05),且垄沟含水量最高,其次为大垄,小垄最低;播种期0~60 cm土层平均体积含水量全膜双垄沟播与露地平作差异显著(P0.05),升高14.19%,且拔节期以前全膜双垄沟播种植土壤贮水量最高,表明全膜双垄沟播栽培有利于玉米的出苗及前期的生长;全膜双垄沟播栽培较半膜平作增产26.76%,水分利用效率较半膜平作提高14.83%。     

小麦的水分利用效率及其最优化问题

根据田间实测资料分析了小麦水分利用效率的综合指数－Ｐ／Ｅ。水分利用效率的变化是光合和蒸腾综合作用的结果。影响这种变化的主要因子为光照，相对湿度，气孔传导率以及土壤的肥力状况等．。分析表明，作物的“午休”现象是农作物实现水分利用最优的一种适应性调节。     

不同生育期干旱胁迫对温室葡萄WUE、产量及品质的影响

【目的】探讨不同生育期干旱胁迫对设施栽培葡萄水分利用效率、产量和品质的影响。【方法】在甘肃省永登县设施葡萄试验基地开展了葡萄滴灌不同生育期水分调控田间灌溉试验,在葡萄新梢生长、开花、果实膨大、着色成熟期分别以55%田间持水率(θ_f)为灌水下限的干旱胁迫处理,依次为新梢生长期干旱胁迫(PS)、开花期干旱胁迫(FS)、果实膨大期干旱胁迫(ES)、着色成熟期干旱胁迫(CS),其他生育期灌水下限均为75%θ_f;全生育期以75%θ_f为灌水下限的处理为(CK)充分供水,研究了不同处理对葡萄粒径膨大速率、产量、水分利用效率(water use efficiency,WUE)以及品质的影响。【结果】新梢生长期干旱胁迫处理能抑制葡萄粒径膨大,但不会影响其生长的双S变化规律,且复水后粒径恢复生长并出现复水补偿效应;横、纵径在膨大期后14 d左右和52 d左右时达到膨大高峰,且第1次膨大高峰时的膨大速率远大于第2次的;新梢期和着色成熟期干旱胁迫较对照依次增产44.6%、42.5%,WUE依次提高71%、57%,果实膨大期干旱胁迫较CK可减产9.7%,WUE降低1.2%;新梢生长期、开花期和果实膨大期干旱胁迫单穂质量、单粒质量均显著(P<0.05)高于CK,开花期干旱胁迫花青素量显著(P<0.05)高于CK,着色成熟期干旱胁迫果糖、蔗糖、葡萄糖、可溶性固形物量显著(P<0.05)高于CK,并可抑制葡萄果实可滴定酸的积累;隶属函数综合分析表明,着色成熟期干旱胁迫葡萄产量和品质最优。【结论】着色成熟期干旱胁迫为当地设施栽培葡萄最佳的水分调控处理,可达到节水和提高葡萄果实产量和品质的生产效果,其水分调控模式为:土壤含水率为田间持水率的55%～80%,灌水定额为270 m~3/hm~2。     

Evaluating decision rules for dryland rotation crop selection

No-till dryland winter wheat (Triticum aestivum L.)-fallow systems in the central Great Plains have more water available for crop production than the traditional conventionally tilled winter wheat-fallow systems because of greater precipitation storage efficiency. That additional water is used most efficiently when a crop is present to transpire the water, and crop yields respond positively to increases in available soil water. The objective of this study was to evaluate yield, water use efficiency (WUE), precipitation use efficiency (PUE), and net returns of cropping systems where crop choice was based on established crop responses to water use while incorporating a grass/broadleaf rotation. Available soil water at planting was measured at several decision points each year and combined with three levels of expected growing season precipitation (70, 100, 130% of average) to provide input data for water use/yield production functions for seven grain crops and three forage crops. The predicted yields from those production functions were compared against established yield thresholds for each crop, and crops were retained for further consideration if the threshold yield was exceeded. Crop choice was then narrowed by following a rule which rotated summer crops (crops planted in the spring with most of their growth occurring during summer months) with winter crops (crops planted in the fall with most of their growth occurring during the next spring) and also rotating grasses with broadleaf crops. Yields, WUE, PUE, value-basis precipitation use efficiency ($PUE), gross receipts, and net returns from the four opportunity cropping (OC) selection schemes were compared with the same quantities from four set rotations [wheat-fallow (conventional till), (WF (CT)); wheat-fallow (no-till), (WF (NT)); wheat–corn (Zea mays L.)-fallow (no-till), (WCF); wheat–millet (Panicum miliaceum L.) (no-till), (WM)]. Water use efficiency was greater for three of the OC selection schemes than for any of the four set rotations. Precipitation was used more efficiently using two of the OC selection schemes than using any of the four set rotations. Of the four OC cropping decision methods, net returns were greatest for the method that assumed average growing season precipitation and allowed selection from all possible crop choices. The net returns from this system were not different from net returns from WF (CT) and WF (NT). Cropping frequency can be effectively increased in dryland cropping systems by use of crop selection rules based on water use/yield production functions, measured available soil water, and expected precipitation.     

降解地膜对南疆棉田土壤水热及棉花产量的影响

为探讨降解地膜对南疆棉田土壤水热及棉花产量的影响,选取3种氧化-生物双降解地膜[天壮1号(T-1)、天壮2号(T-2)、天壮3号(T-3)]及一种新型生物降解地膜(HS),以PE普通地膜为对照,通过测定棉田降解地膜的降解情况及土壤水热,计算其棉田耗水及土壤生长度日,筛选适宜南疆棉田生产的降解地膜。结果表明:在棉花进入吐絮期时,T-3和HS的降解率达88.6%和58.7%,而T-1和T-2仅为15.9%和13.4%。不同降解地膜对棉田的水热状况也存在一定影响,对于生育期总耗水量而言,T-3和PE的耗水量较大,为688.6 mm和690.7 mm,但T-3的耗水模数明显高于PE处理。在土壤生长度日上,4种降解地膜在棉花全生育期土壤生长度日均低于PE地膜,其中T-3和HS的土壤生长度日比PE地膜低了294.3℃·d和222.8℃·d。在棉花产量和水分利用效率上,T-1比PE高6.2%和7.2%,HS明显低于PE地膜,但T-3和PE地膜差异不大。综上,T-1和T-2增温保墒效果好,产量较高,但降解效果差。T-3降解速度较好,增温保墒的性能低于PE地膜,但能够满足作物对温度和水分的需求,使棉花产量和水分利用效率接近PE地膜。因此,在南疆棉田降解地膜T-3替代PE地膜应用于棉花生产具有一定的可行性。