有机肥等氮替代化肥对红壤团聚体及玉米产量和品质的影响

为研究有机肥等氮替代化肥对土壤结构、玉米产量和品质的影响,设置有机肥等氮替代化肥的10%（M10）、20%（M20）、30%（M30）、40%（M40）,以单施化肥（M0）和不施肥（CK）为对照6个施肥处理,测定玉米不同生育期的土壤团聚体变化状况。结果表明：随有机肥等氮部分替代化肥比例的增加,玉米各生育期土壤>0.25mm水稳性团聚体（R_0.25）、平均质量直径（MWD）、几何平均直径（GWD）不断增加,团聚体破坏率（PAD）、分形维数（D）不断降低。与M0处理相比,M30和M40处理显著提高了玉米子粒产量,表现为M30>M40;M20、M30、M40处理较M0处理玉米子粒蛋白质含量显著增加了13.29%~25.03%,淀粉含量显著增加了39.84%~114.06%,可溶性糖含量显著增加了36.49%~54.05%;蛋白质含量表现为M30和M20处理显著大于M40处理,M30与M20处理间差异不显著;淀粉含量表现为M40>M30>M20,差异显著;可溶性糖含量表现为M40和M30处理显著大于M20处理,M30与M40处理间差异不显著。玉米子粒产量和品质与抽雄期、成熟期土壤团聚体R_0.25呈极显著正相关（P<0.01）,与PAD、D值呈极显著负相关（P<0.01）。因此,玉米生产中,利用有机肥等氮替代化肥培肥土壤,需兼顾玉米产量和品质,30%为适宜的有机肥等氮替代化肥比例。     

株行距及穴苗数的配置对寒地水稻产量和品质的影响

为明确垦稻26和龙粳31高产优质栽培的株行距和穴苗数处理,采取裂区设计进行试验研究。结果表明,最优群体因品种而异,垦稻26在株距10cm、行距30cm、5苗/穴产量最佳,龙粳31则以株距13.3cm、行距27cm、9苗/穴产量最佳;垦稻26在5苗/穴、行株距30cm×10cm处理,有利于提高稻米的碾磨品质,不利于改善稻米的外观品质,营养品质较低,利于改善稻米的食味品质,且食味评分值高达86.5,显著高于最低处理;龙粳31在5苗/穴、行株距27cm×13.3cm处理,碾磨品质较高,不利于营养品质和外观品质的改善,食味品质得到明显改善,食味评分值高达86.0,与最低处理差异达显著水平。因此,高产优质栽培要因品种选择适宜的穴苗数和株行距,是实现水稻高产优质最为快捷、最为经济有效的措施。     

灌水量对不同年代宁夏春小麦光合特性及产量构成因素的影响

为揭示不同灌水量对不同年代春小麦光合特性及产量的影响，以5 个不同年代宁夏春小麦品种（系）为试验材料，在宁夏灌区4 种水分处理条件下，研究了灌水时期对不同年代宁夏春小麦品种光合生理指标及产量因子的影响。结果表明，不同时期灌水对春小麦叶绿素含量、净光合速率(Pn)、蒸腾速率(Tr)、水分利用率(WUE)等生理指标均产生明显影响；T1、T2 处理，‘毛火麦’和‘宁春27 号’的叶绿素含量、Pn、WUE较高，在T1、T2 和T3 处理下其产量与其他品种（系）差异不显著。随着灌水量的增加，灌区品种（系）‘宁春4 号’、‘宁春50 号’和‘J63’的叶绿素含量、Pn、WUE高于‘毛火麦’和‘宁春27 号’且产量正常灌水条件下显著高于其他处理。因此，宁夏灌区在保证分蘖期和拔节期灌水，增加抽穗期灌水，各品种（系）既保持较高水分利用效率，又可以获得较高的产量。     

Improving cereal yield forecasts in Europe – The impact of weather extremes

The impact of extreme events (such as prolonged droughts, heat waves, cold shocks and frost) is poorly represented by most of the existing yield forecasting systems. Two new model-based approaches that account for the impact of extreme weather events on crop production are presented as a way to improve yield forecasts, both based on the Crop Growth Monitoring System (CGMS) of the European Commission. A first approach includes simple relations – consistent with the degree of complexity of the most generic crop simulators – to explicitly model the impact of these events on leaf development and yield formation. A second approach is a hybrid system which adds selected agro-climatic indicators (accounting for drought and cold/heat stress) to the previous one. The new proposed methods, together with the CGMS-standard approach and a system exclusively based on selected agro-climatic indicators, were evaluated in a comparative fashion for their forecasting reliability. The four systems were assessed for the main micro- and macro-thermal cereal crops grown in highly productive European countries. The workflow included the statistical post-processing of model outputs aggregated at national level with historical series (1995–2013) of official yields, followed by a cross-validation for forecasting events triggered at flowering, maturity and at an intermediate stage. With the system based on agro-climatic indicators, satisfactory performances were limited to microthermal crops grown in Mediterranean environments (i.e. crop production systems mainly driven by rainfall distribution). Compared to CGMS-standard system, the newly proposed approaches increased the forecasting reliability in 94% of the combinations crop × country × forecasting moment. In particular, the explicit simulation of the impact of extreme events explained a large part of the inter-annual variability (up to +44% for spring barley in Poland), while the addition of agro-climatic indicators to the workflow mostly added accuracy to an already satisfactory forecasting system.     

氮素营养对马铃薯产量形成特性及品质的影响

为优化旱作马铃薯氮素施用量,进一步提高马铃薯产量和改善薯块品质,通过盆栽种植方式,研究氮素营养对马铃薯干物质积累量、根冠比、产量及薯块品质的影响。结果表明:施氮量为190 kg/hm~2时,马铃薯各生育时期干物质积累量、根冠比和单株产量最高,根据一元二次拟合方程得出最佳施氮量为206.39 kg/hm~2,此时马铃薯单株产量为388.22 g,与实际最佳施氮量接近;马铃薯薯块淀粉和VC含量均在施氮量为190 kg/hm~2时最高,薯块蛋白质含量随氮素的增加呈递增趋势,而有机酸含量随氮素增加呈先增后降的趋势,在施氮量为350 kg/hm~2时达到最大值。在试验条件下,综合分析马铃薯产量形成特性及各品质指标,马铃薯氮素最适施用量为190~206.39 kg/hm~2。     

不同规格穴盘育苗对茄苗及其栽培效益的影响

为完善茄子穴盘育苗技术,对比研究了不同规格穴盘育苗的茄苗素质及栽培效益。结果表明:32孔规格穴盘育苗比50孔茄苗素质明显提升;移栽单栋钢架大棚后,32孔穴盘育苗的茄子早熟性比50孔穴盘育苗平均提前5 d,总产量增加15.3%;667 m~2投入成本32孔穴盘育苗比50孔穴盘育苗增加75.3%(35.6元),而收益增加了2 427.9元。因此建议大棚茄子种植采用32孔规格穴盘进行育苗。     

钾肥减量分期施用对莴笋产量和品质的效应研究

通过大田试验研究了紫色菜园土壤钾肥减量分期施用对莴笋产量和品质的影响。结果表明：两个试验点钾肥减量10%~30%分期施用对莴笋产量有提高作用，各处理以K2（钾肥减量10%分期等量追施）效应最好，增产最大（4.2%和4.5%）、施肥利润最高（84923元/hm²和72075元/hm²）。两个试验点莴笋叶维生素C含量均呈下降趋势，K2处理较常规施肥(CK)处理均显著降低莴笋叶维生素C含量（8.0%和8.7%）；而莴笋茎维生素C含量变化规律不一致。钾肥减量分期施用降低两个试验点莴笋叶和茎硝酸盐含量，以K4处理（钾肥减量30%分期等量追施）降低作用最大；从莴笋叶和茎糖组分的均衡性看，以K3处理最好。钾肥减量分期施用对两个试验点莴笋叶必需氨基酸含量有显著增加作用，改善叶氨基酸品质性状，但降低莴笋茎必需氨基酸含量和品质性状；莴笋氨基酸品质性状以K4处理为最优，其次是K2处理。综合考虑莴笋产量和品质，紫色菜园土壤以K2处理（钾肥减量10%分期等量追施）最优。     

滴灌条件下秸秆覆盖和土壤含水量对冬小麦灌浆特性的影响

为阐明滴灌条件下秸秆覆盖和土壤含水量以及两因素交互作用对冬小麦籽粒灌浆、产量形成的影响,以冬小麦矮抗58为试验材料,设计了秸秆处理(覆盖T、不覆盖T0)与土壤相对含水量(40%(W1)、50%(W2)、60%(W3)、70%(W4)4个水平)两因素裂区试验。结果表明:Richards方程拟合秸秆覆盖和水分调控下冬小麦籽粒灌浆过程的决定系数在0.977 5~0.999 6,达到极显著水平。秸秆覆盖和水分调控间的交互作用对除最大灌浆速率和平均灌浆速率(V)外其他冬小麦籽粒灌浆特征参数的影响达到显著或极显著水平。其中,秸秆覆盖下土壤相对含水量60%(TW3)处理组合具有最长的灌浆持续期T(51.91 d),最长的灌浆中期持续期T_2(15.230 d)和灌浆后期持续期T_3(26.556 d),最大的灌浆中期灌浆速率R_2(0.897 mg/d)和灌浆后期灌浆速率R_3(1.365 mg/d)。产量、水分利用效率和耗水量的二次曲线关系表明,在耗水量240~270 mm可达到产量与水分利用效率双高的效果。本试验中以秸秆覆盖与土壤相对含水量60%(TW3)处理组合水分利用效率最高(29.02 kg/(mm·hm~2)),较秸秆覆盖下土壤相对含水量的70%(TW4)提高了5.30%;产量为7 097.7 kg/hm~2,与TW4处理组合差异不显著。     

Short-term water management at early filling stage improves early-season rice performance under high temperature stress in South China

Asymmetric warming and frequent temperature extremes are the consequences of climate change that are affecting crop growth and productivity over the globe while heat stress at early filling stage is of serious concern for the early-season rice in double cropping rice system of South China. In present study we assessed different short-term water management strategies to cope with the high temperature at early filling stage in rice. Water was applied as flood irrigation at two various depths i.e., 4–5 cm (I1) and 5–10 cm (I2) during 9:00–18:00 and then drained off at 18:00 as well as applied over-head during different time spans i.e., over-head sprinkle irrigation during 11:00–12:00, 13:00–14:00 and 14:00–15:00 at 60–80% relative humidity (RH) at early filling stage and regarded as S1, S2 and S3, respectively. A control was maintained with the maintenance of 1 cm water layer as normal farmer practice of this region. A fragrant rice cultivar, ‘Yuxiangyouzhan’ in early March (regarded as early season rice) in both 2014–15 and the effectiveness of different water management strategies were measured by estimating physio-biochemical responses, photosynthesis, yield and quality of rice exposed to high temperature stress at early filling stage. Our results showed that water treatments lowered lipid peroxidation (in terms of reduced malondialdehyde (MDA) contents) whilst proline and protein contents were affected differently. The water treatments also regulated the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), nevertheless, improved plant photosynthesis and gas exchange, rice yield and quality attributes considerably by lowering severity of canopy temperatures than control (CK). On average, both flood and sprinkler water application were proved effective against high temperature stress, nonetheless, flood irrigated treatments were remained more effective than sprinkler which provided 26.58 and 43.63% higher grain yields in 2014–15, respectively than CK. On average, 5.58 and 11.92% higher grain yields were recorded in flood irrigation than sprinkler irrigation whereas among individual water application treatments, I1 was noted as the most effective regarding grain yield of rice (26.76 and 49.35% higher yield than CK) in both years which suggests that maintenance of 4–5 cm water layer might be helpful for the rice to withstand against high temperature stress at post heading and/or early filling stage in early-season rice production in South China.     

不同灌水策略对夏玉米水分利用效率和产量构成要素的影响

于2013—2014年在河南商丘开展了5个灌水处理(T1:苗期水45 mm+拔节水60 mm+灌浆水60 mm+成熟期水45mm,T2:苗期水45 mm+拔节水60 mm+灌浆水60 mm,T3:拔节水60 mm+灌浆水60 mm,T4:拔节水60 mm,T5:灌浆水60 mm)的田间试验,研究了不同灌水处理对夏玉米阶段耗水量、总耗水量、产量、水分利用效率、收获穗数、穗粒数、百粒质量、行粒数的影响。结果表明,夏玉米不同生长阶段灌水处理的耗水量均显著大于不灌水处理(P0.05),且随着整个生育期灌水次数和灌水量的增加,总耗水量显著提高。2013年和2014年,灌拔节水和灌浆水处理(T3)的总耗水量显著低于T1处理(P0.05),产量分别下降8.0%和8.9%,水分利用效率则分别提高5.3%和0.5%。灌水显著影响了夏玉米的收获穗数、穗粒数和百粒质量。2 a的苗期灌水处理(T1和T2)显著提高了夏玉米的收获穗数(P0.05),拔节期和灌浆期灌水处理(T3)的穗粒数和百粒质量均显著大于只灌拔节水(T4)和只灌灌浆水(T5)的处理(P0.05),但收获穗数差异不显著。在节水灌溉的条件下,黄淮海平原夏玉米主产区要实现较高的产量和水分利用效率,灌拔节水和灌浆水是最基本的灌水策略。