荒漠绿洲不同种植方式对青贮玉米产量及水肥利用效率的影响

合理的种植方式可以在不增加灌溉耗水量的前提下,利用植物个体间的正相互作用关系和群体适应特点来达到提高作物产量和水分利用效率的目的。通过田间试验,研究了河西走廊黑河中游边缘绿洲区1穴1株、1穴2株和1穴3株种植方式对青贮玉米产量及水肥利用效率的影响。结果表明,1穴2株和1穴3株的地上生物产量均高于1穴1株,1穴2株最高,鲜重为102.9 t/hm~2,比1穴1株提高了29.4%;1穴2株与1穴1株之间存在显著差异(P0.05),1穴3株与1穴1株之间差异不显著(P0.05)。同样,1穴2株和1穴3株的地上生物产量水肥利用效率也均高于1穴1株,1穴2株的水分和氮肥利用效率也均最高,分别为9.3 kg/m~3和342.9 kg/kg;1穴2株与1穴1株之间存在显著差异(P0.05),1穴3株与1穴1株之间差异不显著(P0.05)。在河西走廊边缘绿洲区,采用1穴2株的种植方式能显著提高青贮玉米的地上生物产量和水肥利用效率,可在生产中推广应用。     

Effects of water limitation on yield advantage and water use in wheat (Triticum aestivum L.)/maize (Zea mays L.) strip intercropping

Wheat (Triticum aestivum L.)/maize (Zea mays L.) strip intercropping is widely practiced in arid regions of northwestern China because of its high land use efficiency. However, its sustainability has been questioned because it consumes much more water than sole cropped wheat or maize. The present study was conducted to investigate the effects of water limitation on the yield advantage and water use of this system. Three field experiments were conducted in the Hetao Irrigation District in Inner Mongolia during the growing seasons of 2012–2014. Each experiment comprised two water applications, in which one was full irrigation and the other was a period of water limitation during the co-growth period of intercropping.The interspecific competition in wheat/maize intercropping was intensified by water stress. For water limitation applied during the wheat booting/maize V5 stage (Exp. I, second irrigation was not applied), the yield advantage of intercropped wheat (IW) over sole wheat was enhanced, whereas that of intercropped maize (IM) over sole maize was reduced compared with full irrigated treatments; for water limitation applied during the wheat jointing/maize V2 stage (Exp. II, first irrigation was not applied), the yield advantages of both IW and IM were greatly reduced; for water limitation applied during the wheat grain filling/maize V9 stage (Exp. III, third irrigation was not applied), the yield advantage of IW was slightly improved, whereas that of IM was reduced. The yield advantage of intercropping under limited irrigation was 25%, 3%, and 18% in Exps. I–III, respectively, whereas that under full irrigation ranged between 22 and 24%.Under well-watered conditions, wheat/maize intercropping used 24–29% more water than the weighted means of sole crops with the water use efficiency equivalent to sole crops. After the application of water limitation, 60 mm irrigation water was saved by intercropping every year, whereas the reduction of water use ranged from 25.1 to 70.8 mm; the changes in water use of intercropping relative to sole crops was reduced to 18–24%; the changes in water use efficiency stayed at nearly zero in Exps. I and III but decreased to a value of −13% in Exp. II. These results indicated that water limitation could be applied during wheat booting or filling stage in wheat/maize intercropping to save irrigation water in our study area.     

Optimized single irrigation can achieve high corn yield and water use efficiency in the Corn Belt of Northeast China

Decreasing the corn (Zea mays L.) gap between the potential yield and farm yield and reducing the risk of grain yield of drought are very important for corn production in the Corn Belt of Northeast China (CBNC). To achieve a high and stable corn yield, the effects of supplementary irrigation on yield, water use efficiency (WUE) and irrigation water use efficiency (IWUE) were studied using a modelling approach. The Root Zone Water Quality Model 2 was parameterized and evaluated using two years of experimental data in aeolian sandy soil and black soil. The evaluated model was then used to investigate responses to various irrigation strategies (rainfed, full irrigation and 12 single irrigation scenarios) using long-term weather data from 1980 to 2012. Full irrigation guarantees a high and stable corn grain yield (12.92 Mg ha⁻¹ and has a coefficient of variation (CV) of 14.8% in aeolian sandy soil; 12.30 kg Ma⁻¹ and CV of 11.1% in black soil), but has a low water use efficiency (19.92 and 21.81 kg ha⁻¹ mm⁻¹) and a low irrigation water use efficiency (10.01 and 11.03 kg ha⁻¹ mm⁻¹). A single irrigation can increase corn yields by 3–35% for aeolian sandy soil and 5–35% for black soil over different irrigation dates compared with no irrigation. The most suitable single irrigation date was during late June to early July for aeolian sandy soil (yield = 10.73 Mg ha⁻¹ and WUE = 27.94 kg ha⁻¹ mm⁻¹) and early to mid-July for black soil (yield = 11.20 Mg ha⁻¹ and WUE = 27.70 kg ha⁻¹ mm⁻¹). The lowest yield risk of falling short of the yield goal of 8, 9, and 10 Mg ha⁻¹ were 9.1%, 18.2%, and 33.33% in aeolian sandy soil and 3.0%, 15.25, and 21.2% in black soil when an optimized single irrigation was applied in late June or early July, respectively. Therefore, an optimized single irrigation should be applied in late June to early July with the irrigation amount to refill soil water storage of root zone to field capacity in CBNC.     

Stable isotope technique in the evaluation of tillage and fertilizer effects on soil carbon and nitrogen sequestration and water use efficiency

Agricultural soil could be made to serve as a sink rather than a source of greenhouse gases by suitable soil management. This study was, therefore, conducted to assess the impact of tillage and fertilizer application on soil and plant carbon and nitrogen fractionation and intrinsic water use efficiency (iWUE). The experiment was a split–split-plot factorial design with three replications. The main plot consisted of two tillage treatments: zero tillage (ZT) and conventional tillage (CT). The sub-plot contained four NPK fertilizer treatments (0, 90, 120 and 150 kg N ha⁻¹), while the sub–sub-plot comprised three poultry manure (PM) treatments (0, 10 and 20 Mg ha⁻¹). Soil carbon and nitrogen sequestration were evaluated using stable isotope of carbon (δ¹³C) and nitrogen (δ¹⁵N). The δ¹³C in maize plant was used to obtain iWUE. It was observed that soil δ¹³C and δ¹⁵N were more depleted under ZT than CT and in plots treated with 20 Mg ha⁻¹ PM (PM₂₀) implying carbon and nitrogen sequestration under ZT and by PM₂₀. Relative to the control, application of PM₂₀ raised soil δ¹⁵N enrichment by 82% and 96% under CT and ZT, respectively. Higher iWUE of 25.7% was obtained under CT and was significantly higher than the iWUE values under ZT in the second year of the study while the iWUE was significantly lower with PM₂₀ application than other fertilizer treatments. The significant δ¹³C depletion and hence lower iWUE with combination of NPK fertilizer and PM under CT than the control implied that soil disturbance under tilled plots was mediated by combined nutrient management thereby limiting soil C available for fractionation resulting in lower iWUE. This suggests that conservation tillage such as zero tillage and integrated application of organic and inorganic fertilizers are good strategies for reducing soil carbon and nitrogen emission.     

有机培肥与轮耕方式对夏玉米田土壤碳氮和产量的影响

探明不同轮耕和有机培肥方式对夏玉米田土壤碳氮及其酶活性的影响,对提升农田土壤肥力及促进玉米高产具有重要意义。设秸秆(P)与牛粪(F)两种有机培肥方式和小麦季旋耕-玉米季深松(RS)、小麦季深松-玉米季免耕(SN)、小麦季翻耕-玉米季免耕(CN) 3种轮耕方式,共6个处理,于2015—2016和2016—2017玉米收获期采样测定,研究了不同有机培肥和轮耕方式对土壤碳氮及其酶活性和作物产量的影响。结果表明,轮耕方式、有机肥及其交互效应对土壤肥力有显著影响。在0～10 cm和10～20 cm土层,与轮耕方式CN相比, RS和SN能够显著提高土壤有机碳、全氮含量和脲酶、蔗糖酶活性。在轮耕方式RS中,与施用牛粪相比,秸秆还田显著提高了10～20 cm、20～30 cm和30～40 cm土层的有机碳含量,增加了10～20 cm土层的全氮含量和蔗糖酶活性。在轮耕方式SN中,与秸秆还田相比,施用牛粪显著提高了0～10 cm和10～20 cm土层的有机碳、全氮含量和蔗糖酶活性,增加了各土层脲酶活性。与秸秆还田+翻耕-免耕(PCN)相比,秸秆还田+旋耕-深松(PRS)和施用牛粪+深松-免耕(FSN)能显著提高土壤肥力。在0～10 cm和10～20 cm土层,各处理中以FSN增加土壤有机碳、全氮含量和蔗糖酶、脲酶活性最为明显。轮耕方式、有机肥及其交互效应对产量有显著影响。轮耕方式RS和SN的产量较CN分别显著提高了1.89%～10.49%、5.44%～11.99%。在轮耕方式RS中,产量表现为秸秆还田较施用牛粪显著提高了2.91%～3.11%;而在轮耕方式SN中,则表现为秸秆还田较施用牛粪显著降低了5.02%～9.07%。两年玉米产量均表现为FSNPRSFRSPSNFCNPCN。综上所述,在6种处理中,处理FSN在提高土壤肥力和产量方面最为显著,可以作为试验及周边地区适宜的轮耕培肥方式。     

土壤耕作方式对小麦干物质生产和水分利用效率的影响

2007—2010小麦生长季,以高产小麦品种济麦22为材料,利用测墒补灌技术确定灌水量,研究高产条件下条旋耕、深松+条旋耕、旋耕、深松+旋耕和翻耕5种耕作方式对小麦的耗水特性、干物质积累与分配、籽粒产量及水分利用效率的影响。结果表明,深松+条旋耕和深松+旋耕的农田耗水量和0~200 cm土层的土壤贮水消耗量高于条旋耕和旋耕处理,深松+条旋耕的小麦株间蒸发量低于深松+旋耕和翻耕处理。深松+条旋耕和深松+旋耕成熟期的干物质积累总量、籽粒的干物质分配量及分配比例和开花后干物质同化量对籽粒的贡献率均高于翻耕处理,翻耕高于旋耕和条旋耕处理,条旋耕最低。深松+条旋耕三个生长季均获得高的籽粒产量,分别为9 409.01 kg hm^-2、9 613.86 kg hm^-2和9 698.42 kg hm^-2,与深松+旋耕处理无显著差异,翻耕处理次之,条旋耕和旋耕低于上述处理,条旋耕最低。深松+条旋耕处理的水分利用效率在2007—2008生长季与深松+旋耕处理无显著差异;在2008—2010生长季最高,分别为21.39 kg hm^-2 mm^-1和22.09kg hm^-2 mm^-1,深松+旋耕处理次之,旋耕和条旋耕低于翻耕处理。在本试验条件下,深松+条旋耕是兼顾高产节水的最优耕作方式。     

The influence of crop sequence on fungicide and herbicide use intensities in North German arable farming

The reduction of pesticide use intensity is a societal and political ambition. Crop rotation is one important method to control pests and diseases in arable farming. We investigated the contribution of crop rotation to the variability of herbicide and fungicide use of 60 farms in four regions of Northern Germany. Our study aimed at answering the question: do diverse crop sequences lead to reduced herbicide and fungicide use in arable farming?Ten-year data on chemical plant protection measures and field management were examined for six field crops. We classified crop sequences (triplets of three succeeding crops) according to their susceptibility for weeds and diseases (= ’riskiness’). The Treatment Frequency Index (TFI) of the last crop in the triplet was set in relation to the crop triplet riskiness, additionally also in combination with tillage.In general, herbicide and fungicide use intensities were smaller in more diverse crop sequences. Diversified cereal sequences, involving roots and tubers, maize or spring cereals were less dependent on herbicides. Cultivation of maize in three subsequent years increased herbicide use. Crop sequences including high proportion of winter cereals increased fungicide use in cereals, while roots and tubers, winter oilseed rape and set-aside in the crop sequence decreased it. In winter oilseed rape, sequences with roots and tubers also increased fungicide use. In sugar beets, sequences with maize or a high concentration of sugar beets led to increasing fungicide use. If farmers chose riskier crop sequences tillage by plough decreased the need for herbicide and fungicide use.To reduce herbicide and fungicide use intensities we recommend increasing the diversity of crop rotations, including a higher number of crops per rotation together with ploughing. Simplifying both crop sequence diversity and tillage intensity implies higher use of herbicides and fungicides. Results will be useful for convincing farmers to diversify crop sequences.     

Effects of controlled irrigation and drainage on growth,grain yield and water use in paddy rice

Rice is subjected to excessive waterlogging and flash-flooding on large areas in south China. A study on water use, growth and yield effects of controlled irrigation and drainage (CID) of paddy rice at four stages was conducted in specially designed experimental tanks. The treatments were (1) CID during Stage I of tillering stage (CID-Stage I), (2) CID during Stage II of booting stage (CID-Stage II), (3) CID during Stage III of heading to flowering stage (CID-Stage III), (4) CID during Stage IV of milky stage (CID-Stage IV), (5) alternate wetting and drying irrigation during the whole stage (CK). Compared with CK, CID reduced drainage volume with 15.8–31.3% in 2008, and 13.5–28.3% in 2009, and increased the efficiency of available rainfall and irrigation by 1.98–3.46% in both years. Irrigation water application during the whole growing season across the 2 years, on average, was only 81.8%, 91.1%, 93.9%, and 94.5%, respectively, of that applied to CK. A strong reduction in root length, root weight, root-shoot ratio and harvest index were observed, however, shoot weight and total dry mass is increased from the treatments of CID-Stage II, CID-Stage III and CID-Stage IV. The highest radiation use efficiency values were for CID-Stage IV. The responses of CID from vegetative plants at Stage I and Stage II were greater than in generative plants at the latter two stages. CID-Stage II had only a small effect on subsequent development and grain yield. This decrease in grain yield to less than 7.88% and 5.72% of CK was due to reduced number of spikelets per panicle in one trial, and reduced panicle number per unit area in another. The CID-Stage I treatment showed the lowest grain yield among the treatments and reduced it by 23.3% in 2008 and by 17.3% in 2009, due to the decreases in the percentage of filled grains and total number of panicles. The effect of stress was associated with low dry matter production during the flooding stress period as well as during the stress withdrawal period following the stress. With regards to irrigation water use efficiency, it was increased under the first two treatments, and by from a minimum of 101% to a maximum of 110%.     

不同水氮供应对水稻产量、吸氮量及水氮利用效率的影响

通过两年在宁夏引黄灌区田间小区试验,以宁粳28号为材料,研究了3个不同灌水量与4个施氮水平对水稻产量、吸氮量及水氮利用效率的影响。结果表明,在相同灌水量条件下,两年水稻的籽粒和秸秆产量均随着施氮量的增加呈增加的趋势。不同灌水量对水稻产量影响不大,但施氮量却显著地影响着其产量和地上部吸氮量。灌水量或施氮量对水稻的株高、穗长、穗数和千粒重均无显著影响。05年和06年水稻氮肥利用率分别在5.1%~37.6%和14.1%~25.0%之间。相同施氮水平下,05年水稻氮肥生理利用率随着灌水量的增加而增加,06年水稻表现出相反的趋势。两年水稻的氮肥农学利用率在8.3~19.3 kg/kg之间。氮肥偏生产力在同一灌水水平下,都随着施氮量的增加而降低,在同一施氮水平下,灌水量处理间差异并不大。相同施氮水平下,水稻的灌水生产率随着灌水量的增加而降低。从产量、吸氮量及水氮利用效率等因素考虑,本试验水氮合理配比是灌水量控制在1.2×104 m3/hm2左右,施氮量240 kg N/hm2左右。     

水氮配置对华北冬小麦-夏玉米种植体系氮素利用及土壤硝态氮残留的影响

针对华北平原冬小麦-夏玉米轮作体系存在过量的水、氮投入问题,本研究于2008 -2010年在河北吴桥设置了传统水氮、传统水氮调整、节水减氮和最少水氮4个水氮模式,以分析减少水氮投入后冬小麦-夏玉米体系的产量、氮素利用和土壤氮残留情况.结果表明:与传统水氮相比,节水减氮模式的氮肥投入量下降55％,水分投入量下降36.6％...     

节水减氮对土壤硝态氮分布和冬小麦水氮利用效率的影响

针对当前关中平原冬小麦生产中氮肥投入过量、灌溉水资源不足的问题,研究节水减氮栽培模式下冬小麦籽粒产量、水氮利用及硝态氮淋失情况,能为确定冬小麦节水减肥环保增效的生产模式提供理论依据。于2017—2019年在陕西杨凌开展冬小麦节水减氮田间栽培试验,采用二因素裂区设计,施氮量为主处理,灌水量为副处理,设施氮量处理N300 (300 kg hm^–2)、N225 (225 kg hm^–2)、N150 (150 kg hm^–2)、N75 (75 kg hm^–2)、N0 (不施氮)和灌水量处理W2 (1200 m³ hm^–2)、W1 (600 m³ hm^–2)、W0 (0),分析小麦产量、水氮利用效率及土壤硝态氮淋失情况。结果表明,2017—2018年和2018—2019年小麦季灌水处理较不灌水处理分别增产14.88%～15.01%和4.11～4.16倍,但处理间差异不显著,而越冬期灌水600 m³ h...     

全生物降解地膜覆盖对旱地土壤水分状况及春小麦产量和水分利用效率的影响

The purpose of this study was to investigate the ecological effect of full biodegradable film mulching and its effect on the production of spring wheat, and to seek a green, efficient and sustainable coverage in the semi-arid area of the Northwest Loess Plateau. Taking the uncovered land as the control (CK), to systematically studied the effects of full biodegradable film mulching (BM) and the polyethylene film mulching (PM) with bunch planting on soil water status, rain fallow efficiency and its impact on yield and water use efficiency of dryland spring wheat from 2015 to 2018. The results showed that both BM and PM significantly increased the water storage of 0-200 cm soil layer and rain fallow efficiency in each growth period of spring wheat, but there was not significant differences between BM and PM. From 2015 to 2018, the water storage of BM increased by 9.5 mm, 14.2 mm, 25.0 mm, and 39.0 mm respectively compared with CK. In the fourth year of continuous cropping, the water storage of PM, BM and CK 0-200 cm soil layers were 347.5 mm, 345.5 mm and 320.0 mm, respectively. Compared with CK, the rain fallow efficiency of BM and PM increased by 39.63% and 43.98%, respectively, which effectively alleviated the risk of spring drought in the next season. BM was similar to PM in seedling rate, the number of productive ears and the percentage of productive spike, and significantly higher than CK. The number of BM seedlings increased by 15.87% compared with CK in dry year, the number of productive ears increased by 14.70% on average in other years except 2015, and the percentage of productive spike increased by 3.08% on average in four years. The total amount of dry matter accumulation of BM was basically the same as PM, and before anthesis was slightly lower than PM, but higher than PM after anthesis, which was more conducive to grain filling and yield formation, and the amount of dry matter accumulation of both BM and PM are significantly higher than CK in each growth period. The annual average water consumption of PM, BM and CK was 287.46 mm, 289.76 mm, and 276.06 mm, respectively, and compared with PM, BM increased the evaporation water consumption. Compared with CK, the grain yield of BM and PM increased 48.07% and 54.95% respectively, and water use efficiency increased 46.08% and 56.07% in four years, there was not significant differences between BM and PM. There was not significant differences in soil water effect and yield effect between the full biodegradable film and PE film, and the full biodegradable film can be applied to the whole field soil-plastic mulching with bunch planting of spring wheat in dry land and provide technical support for the green and efficient production of wheat in dry land.     

The effects of regulated and continuous deficit irrigation on the water use, growth and yield of olive trees

Important savings in the levels of irrigation without an associated penalty in yield have been reported for olive under deficit irrigation strategies. Full irrigation (C), continuous deficit irrigation (CDI) and regulated deficit irrigation (RDI), were compared from 2004 to 2006 in Cordoba, southern Spain, in terms of seasonal evapotranspiration (ET), growth and yield in mature olive trees (Olea europaea L. cv. ‘Arbequina’). In deficit treatments, the total amount of irrigation was around 25% of that of the Control while ET was 65–70% of that of C. Deficit treatments strongly reduced vegetative growth, but only slightly reduced the final fruit volume. Water stress caused a higher reduction in fresh fruit yield than oil yield due to a higher oil concentration in deficit irrigated trees, without differences between CDI and RDI. Therefore, both irrigation strategies may be used in olive to save a significant amount of irrigation with moderate reductions (about 15%) in oil yield. The amount of oil produced per unit intercepted PAR was almost the same for all the treatments, which suggests that olive oil yield may be calculated from intercepted radiation even under moderate water stress.     

Organic amendment and minimum tillage in winter wheat grown in Mediterranean conditions: Effects on yield performance,soil fertility and environmental impact

The experiment was conducted to evaluate the agronomic benefit of the application of organic fertilizers combined with different soil tillage on quantitative and qualitative components of winter wheat (Triticum durum Desf., cv. ‘Simeto’) and on chemical soil fertility parameters. The environmental impact, due to heavy metals introduced in soil-plant system, was further investigated. Soil tillage treatments consisted of conventional (CT) and minimum tillage (MT). Fertilization treatments were: mineral at 100 kg N ha⁻¹ (N_min); municipal solid waste compost at 100 kg N ha⁻¹ (N_comp); 50 kg N ha⁻¹ of both compost and mineral fertilizers (N_mix); sewage sludge at 100 kg N ha⁻¹ (N_ss). These treatments were compared with an unfertilized control (N₀). No significant difference was observed between the two soil tillage treatments for quantitative yield production, while among the fertilization treatments N_ss did not show any significant difference compared to N_min. At the end of the research, the fertility of the soil (oxidable carbon, total nitrogen, available phosphorus) was on average higher in N_comp and N_ss treatments compared to the N₀ and N_min ones. The overall distribution of heavy metals in soil-plant system respect to the different fertilizer treatments has not allowed to grouped their effects with Principal Components Analysis. This result showed that the amount of potential pollutants applied by organic amendments did not modified the dynamic equilibrium of the soil–plant system. The MT, as well as the fertilization with the application of sewage sludge (N_ss), allowed to reach productive performance similar to conventional management (CT with N_min). Here we demonstrate that, in the short term period, sustainable agronomical techniques can replace the conventional one with environmental benefit.     

时空交替间隔灌溉对夏玉米田水分和产量形成的影响

为了给夏玉米有效灌溉提供科学依据,研究了夏玉米不同生育时期和不同根区实施交替补灌对农田蒸散、夏玉米产量形成以及水分利用效率的影响,共设9个处理：拔节期和抽穗期充分供水（ T1N1）、拔节期充分供水＋抽穗期中度水分亏缺（T1N2）、拔节期充分供水＋抽穗期重度水分亏缺（T1N3）、拔节期中度水分亏缺＋抽穗期充分供水（T2N1）、拔节期中度水分亏缺＋抽穗期中度水分亏缺（T2N2）、拔节期中度水分亏缺＋抽穗期重度水分亏缺（T2N3）、拔节期重度水分亏缺＋抽穗期充分供水（T3N1）、拔节期重度水分亏缺＋抽穗期中度水分亏缺（T3N2）、拔节期重度水分亏缺＋抽穗期重度水分亏缺（ T3 N3）。结果表明：各处理在全生育期内的棵间土壤蒸发量变化趋势均呈脉冲状,且各生育阶段棵间土壤蒸发量占阶段蒸散量比例在播种-灌浆-成熟阶段均表现出先降后升的趋势。整个生育期间棵间土壤蒸发量（E）/总蒸散量（ET）为34．89％～52．19％,并随着水分亏缺程度加剧而降低。产量表现为T1N2＞T2N1＞T1 N3＞T2 N2＞T2 N3＞T1 N1＞T3 N1＞T3 N2＞T3 N3,其中T1 N2处理产量极显著高于其他处理。 T1 N2处理的作物水分利用效率最高（27．08 kg/（hm2· mm））,分别比 T3N1、T3N2、T3N3和 T1N1处理高12．78％,16．90％,19．79％,26.92％,拔节期和抽穗期均为高水分的T1 N1处理最低,其他处理随着总补灌量的减少逐渐下降。在黄淮海夏玉米区,采用时空交替灌溉方式：拔节期充分补灌（田间持水量的80％）和抽穗期补灌量适度减少（田间持水量的65％）,有利于夏玉米产量和土壤水分高效利用的同步提升。     

灌水量对小麦氮素吸收、分配、利用及产量与品质的影响

以济麦20和泰山23为试验材料, 在大田条件下研究了灌水量对小麦氮素吸收、分配、利用和籽粒产量与品质及耗水量、水分利用率的影响。2004—2005年生长季, 小麦生育期间降水量为196.10 mm, 两品种的氮素吸收效率、籽粒的氮素积累量和氮肥生产效率均为不灌水处理低于灌水处理, 但籽粒氮素分配比例和氮素利用效率表现为不灌水处理高于灌水处理。拔节期前, 两品种的氮素吸收强度灌水180 mm处理高于灌水240 mm和300 mm两处理, 拔节期后反之; 成熟期, 植株氮素积累量和氮素吸收效率在各灌水处理间无显著差异。济麦20籽粒的氮素积累量和分配比例、氮素利用效率和氮肥生产效率, 均以灌水240 mm处理高于灌水180 mm和300 mm处理; 灌水180 mm和240 mm处理的籽粒产量分别达8 701.23 kg hm^-2和9 159.30 kg hm^-2, 耗水量为469.29 mm和534.48 mm, 两处理间籽粒品质无显著差异, 且均优于灌水300 mm处理。泰山23籽粒中氮素积累量及分配比例、氮素利用效率、氮肥生产效率和籽粒品质, 在各灌水处理间无显著差异; 灌水180 mm和240 mm处理籽粒产量显著高于其他处理, 分别达9 682.65 kg hm^-2和9 698.55 kg hm^-2, 其耗水量分别为468.54 mm和532.35 mm。两品种的水分利用率均随灌水量增加而降低。在2006—2007年生长季, 小麦生育期间降水量为171.30 mm, 济麦20和泰山23均以灌水240 mm处理的籽粒产量和水分利用率最高, 其耗水量分别为490.88 mm和474.88 mm。综合考虑产量、品质、氮素利用效率、氮肥生产效率和水分利用率, 生产中济麦20生育期灌水量以180~240 mm为宜; 泰山23在降水量达196 mm条件下, 灌水量以180 mm为宜, 在降水量为170 mm条件下, 灌水量以240 mm为宜。     

不同耕作方式对旱区春谷根系发育、产量及水分利用效率的影响

不同耕作方式对旱区春播谷子根系的生长发育有极为重要的影响。以晋谷21号为材料,以传统旋耕为对照,研究了翻耕、秋季深松和春季深松3种耕作方式对谷子地下根系性状与垂直分布、产量和水分利用效率的影响。结果表明,3种耕作方式均能提高谷子根系的长度、表面积、体积、平均直径与干重,深松处理能使谷子根系向40~60cm土层有效生长。与传统旋耕相比,2个深松处理均能显著提高穗长和穗粒重,3种耕作方式的谷子产量较传统旋耕均显著提高,提高幅度排序为春季深松、秋季深松和翻耕,2个深松处理间产量差异未达显著水平。春季深松耕作方式替代传统旋耕能有效提高旱作春谷区的谷子生产水平。     

旱地全膜双垄沟播秋覆膜对玉米产量和水分利用率的影响

在推广应用旱地玉米全膜双垄沟播栽培技术基础上,从进一步减少冬春季土壤水分的无效蒸发、提高土壤含水量、改善玉米经济性状、提高玉米产量入手,进行了全膜双垄沟播秋覆膜对旱地玉米产量和降水利用率影响的试验研究。结果表明,全膜双垄秋覆膜沟播栽培可明显减少冬春季土壤水分的无效蒸发、增加土壤水分含量、玉米的经济性状明显改善,玉米产量比全膜双垄沟播栽培播种前覆膜和半膜覆盖栽培分别增产16.13%和46.08%,增产效果明显;水分生产率比全膜双垄沟播栽培播种前覆膜和半膜覆盖栽培分别提高34.5%和57.8%。     

Analysis of the ozone effect on soybean in the Mediterranean region: II. The consequences on growth, yield and water use efficiency

Soybean plants were subjected, during their growing seasons, to well-watered and water-stressed conditions, and three levels of ozone concentration (zero, low and high) in open top chambers (OTCs). At the end of the soybean growing season accumulated AOT40 values were zero, 3400 and 9000 ppb h for the filtered (control), low and high levels of ozone concentration, respectively.

In well-watered conditions, an increase in ozone concentration led to a reduction in leaf area, dry matter and reproductive organs. Whereas, an increase in ozone had no effect on plants in water-stressed conditions. At a high level of ozone concentration, there was a 47% reduction in yield and a 25% reduction in WUE in comparison with the control treatment. The reduction in yield was due to a lower number of pods per plant and 1000-grain weight. Despite changes in the grain yield, the yield quality was not altered by ozone.

During the 3-year study, AOT40 was significantly correlated with the leaf area and the final above-ground dry matter. The latter was less sensitive to ozone than leaf area. These results were reliable and would be useful in soybean yield-prediction models.

Finally, the conclusion highlights the reliability of the approach adopted, which was to make observations on various time scales (hourly, daily and entire crop cycle).     

灌水量对小麦籽粒粉含量和相关酶活性及水分利用效率的影响

在2004-2005年和2005-2006年小麦生长季,设置不同的灌水时期和灌水量处理,研究了小麦籽粒产量、籽粒淀粉含量、淀粉合成相关酶活性和水分利用效率。结果表明,全生育期不灌水条件下,籽粒中的可溶性淀粉合酶(SSS)和淀粉粒结合态淀粉合酶(GBSS)活性在灌浆初期显著升高,在灌浆中后期显著降低,同时灌浆后期支链淀粉、直链淀粉和总淀粉含量亦显著降低。拔节期和开花期每次灌水60 mm有利于小麦在灌浆中后期保持较高的SSS和GBSS活性,提高灌浆后期籽粒中的支链淀粉、直链淀粉和总淀粉含量;灌水量进一步增加时,灌浆中后期的SSS活性显著降低,GBSS活性升高,灌浆后期的支链淀粉含量降低,直链淀粉含量升高。在两个生长季中拔节期和开花期每次灌水60 mm处理的土壤贮水消耗量较高,水分利用效率最高和籽粒产量较高。在此基础上增加灌水量时,开花至成熟阶段0~60 cm土层的土壤含水量显著升高,土壤贮水消耗量降低,籽粒产量无显著变化,水分利用效率和灌溉水利用效率降低。