Relationship between the Annual Yield of Black-skinned Sugarcane and Meteorological Disasters in Wengyuan County

The GM(1,1)grey model was used to simulate and divide the harvest years of black-skinned sugarcane yield in Wengyuan County during 2006-2021.Based on the meteorological observation data of Wengyuan County during the same period,the impact of major meteorological disasters such as drought,flood and frost in the growth period of black-skinned sugarcane was analyzed.It is believed that the instability of black-skinned sugarcane yield was affected by comprehensive meteorological factors.It is necessary to master the characteristics of local meteorological disasters,conduct scientific cultivation according to local conditions,and continuously improve the meteorological service level of black-skinned sugarcane cultivation.

Effect of reforestation on annual water yield in a large watershed in northeast China

A simplified water balance model in conjunc- tion with an evapotranspiration （ET） model and cumulative forest cover data were used to quantify the changes in annual water yield in response to reforestation in a large watershed, northeast China. Cumulative forest cover increased by 22 %, leading to a significant decrease in estimated annual water yield. Reforestation increased ET （P = 0.0144）, resulting in a remarkable decrease （P = 0.0001） in estimated annual water yield according to the water balance model. Reforestation increased ET by 33 mm and decreased annual water yield by 38 mm per decade. The effect of reforestation on annual water yield can be quantified using a simplified water balance model in a large watershed, although our reforestation area was small （about 20 %） in relation to the total watershed area.

Effect of Dehydrated Digested Effluent of Manure on Yield and Quality of Annual Forages and Soil Chemical Properties in Southern Kyushu, Japan

Digested effluent of manure (DEM) produced by biogas-plants contains many macro- and micro-nutrients. In an experiment conducted in southern Kyushu (Japan), forage crops cultivated after receiving DEM and chemical fertilizers exhibited similar dry matter yields. From a logistical standpoint, however, DEM in liquid form is difficult to handle and apply due to the low concentration of nutrients. To overcome this shortcoming, we prepared dehydrated DEM (DDEM) by adding DEM to cattle manure without disturbing the manure fermentation process. The objective of this research was to evaluate the effect of DDEM on dry matter yield and nitrogen recovery rate in annual dual-cropping systems (summer crop of maize or sorghum and winter crop of Italian ryegrass) that are typical of the region and to compare these results to commercial cattle manure alone, in combination with chemical fertilizer (CM or CM + CF), or no fertilizer application (NF). In both cropping systems, the DDEM treatment produced similar dry matter yields (2.6 to 3.02 kg&middotm-2) and apparent nitrogen recovery rates (43% to 53%) as the CM + CF and CM treatments. This suggests that DDEM can potentially replace chemical fertilizers and commercial cattle manure in the region.

“妃子笑”荔枝高产若干生长发育性状

“妃子笑”荔枝是我国栽培区域最广的荔枝品种,比较研究不同区域“妃子笑”生长发育特性可为树冠、养分管理和成花着果调控及区域适应性发展等参考,为荔枝品种制订高产和克服“大小年”技术方案提供借鉴。2008—2022年,调查统计华南六省(区)北纬18°32′~28°47′的24县(区)39个示范园“妃子笑”物候期;于始花期调查海南、广东、广西和云南省(区)18个果园“妃子笑”结果树枝条、叶片和花穗生长量,并取样分析枝条、叶片、花穗主要养分含量,计算植株不同部位营养需求量。结果表明,主产区“妃子笑”末次秋梢成熟期8月下旬至11月中旬,现“白点”(花穗原基)期11月下旬至翌年2月中旬,盛花期2月上旬至4月上旬,果实成熟期4月下旬至7月底。3次秋梢生长分别约为35.9、39.5和40.2 d,秋梢老熟至现花穗原基(花诱导)约87 d,花穗与花芽分化期约56 d,果实发育期约需63 d。海南等地区“妃子笑”采果后树冠重回缩修剪至1.5 m高,形成矮化树形,而粤西等地修剪至2~3 m高,塑造高大树形。“妃子笑”结果植株采果后秋梢生长1~3次,树冠表面积的平均枝梢数16条/m2,秋梢平均长度37.7 cm,秋梢复叶数17片、叶片数104片。“妃子笑”单株不同部位年生长量,以鲜质量计分别为秋梢枝条16.8 kg,叶片40.2 kg,花穗17.2 kg;以干质量计为秋梢枝条9.50 kg,叶片23.24kg,花穗7.19kg。主要养分含量为秋梢枝条中氮0.76%、磷0.26%、钾0.72%、钙0.54%、镁0.15%;叶片中氮1.79%、磷0.17%、钾0.94%、钙0.77%、镁0.25%;花穗中氮2.20%、磷0.30%、钾1.74%、钙0.32%、镁0.29%。单株50 kg的产量,年度枝叶、花穗和果实生长所需主要元素为氮0.70 kg、磷0.10 kg、钾0.46 kg,秋梢期氮、磷、钾用量分别占比全年用量的71.4%、70.0%、63.0%。从多年产量稳定性看,海南省陵水县、琼海市、海口市,广西北海铁山港区、合浦县,广东省廉江市等地是“妃子笑”适应性表现较好的栽培区。综合而言,随着纬度北移和海拔升高,“妃子笑”物候期延后,果实成熟期持续3个月以上;各地区“妃子笑”物候期相差较大的是末次秋梢成熟期和果实成熟期,差异较小的是花芽诱导期;枝叶养分需求较大,确保秋梢生长量是支撑产量和品质的重要基础。

Yield Production and Energy Budget of Traditional Agricultural Crops in Garhwal Himalaya

The yield production and energy budget of agroecosystem was carried out at three different climatic regions, i.e., tropical, sub-tropical, and temperate in Garhwal Himalaya, India. The total human population was the highest （1 140） in tropical region, followed by 464 in temperate region, and 374 in sub-tropical region. Livestock population had also a similar trend with human population in each climatic region, which was 870, 290, and 188 in the tropical, temperate, and sub-tropical regions, respectively, in winter season, the crop production was the highest （2 332 kg hat yr-l） for Triticum aestivum in tropical region followed by 1 716 kg ha^-1 yr^-1 in sub-tropical region, and 1 473 kg ha^-1 yr^-1 in temperate region. The associated crops were Itordeurn vulgate, Brassica caml ＇stris, and Pisum sativa. However, in summer season, the most contributing crop was Oryza sativa, which had also the highest production in tropical region followed by sub-tropical region, and temperate region, i.e., 1 160, 1096, and 1 076 kg ha^-1 yr^-1, respectively. Other growing crops were Elusine coracana, Vigna mugo, Glycine soja, and Echnochlolafrumentaceae. Brassiea rugosa was the only crop grown in tropical region between the period of winter and summer season. The total root production of crops in each climatic region was the highest in tropical region （1 846.2 kg ha^-1 yr^-1）, followed by temperate region （1 841.5 kg ha^-1 yr^-1） and sub-tropical region （1442.5 kg ha^-1 yr^-1）. However, shoot components of crops were 20 241.5, 17 847.0, and 1 188.3 kg ha^-1 yr^-1, which recorded parallel to root in each climatic region. The root and shoot components of weed decreased with increasing altitudes, which were 105.39 and 1150.5 kg ha^-1 yr^-1 in tropical region, 94.55 and 1147.5 kg ha^-1 yr^-1 in sub-tropical region, and 73.33 and 871.5 kg ha^-1 yr^-1 in temperate region for root and shoot, respectively. In the energy inputs, the most contribution was of compost in each climatic region. Among the region, the highest input of compost was in temperate region followed by sub-tropical, and the lowest in temperate region. The fertilizer input was only recorded from tropical region because of its close connection with market and easy accessibility to the farmer compared to subropical and temperate regions. The energy input ranged from 0.39×10^5 to 0.44× 10^5 MJ ha^-1 （human labour）, 0.84× 10^5 to 1.09× 10^5 MJ ha^-1 （bullock labour）, 0.36×10^5 to 0.45×10^5 MJ ha^-1 （seed）, 16.65 × 10^5 to 32.65 ×10^5 MJ ha^-1 （compost）, while output ranged from 8.44 × 10^5 to 11.01 × 10^5 MJ ha^-1 （agronomic yield）, and 14.22× 10^5 to 19.35 ×10^5 MJ ha^-1 （crop-residue）. The total input was the highest in temperate region, followed by subtropical and tropical region, and the highest output was in tropical region and the lowest in sub-tropical region.

不同种源小白及年增产量和品质的比较与综合评价

目的:为了比较不同种源小白及的年增产量和品质,筛选出综合表现较好的小白及种源。方法:以6个不同种源的小白及为材料,测定年增产量、灰分、浸出物、多糖、黄酮、总酚等指标,并运用方差分析、多重比较、主成分分析对不同种源小白及进行综合评价。结果:不同种源小白及的被测指标存在极显著差异,黄酮含量与年增产量呈极显著正相关,相关系数为0.892;总酚含量与多糖含量呈极显著负相关,相关系数为-0.684;结合主成分分析和综合指数选择法对不同种源小白及的年增产量和品质进行了综合评价,6个种源中三角山和永保村两个种源小白及综合表现最好。结论:三角山种源的小白及浸出物、多糖和总酚含量最高,永保村种源的小白及灰分、多糖、黄酮含量最高,这两个种源的小白及可作为优质种源进行小白及的人工种植试验、育种优良亲本选择,或供进一步的资源开发及利用等。

Estimation of runoff and sediment yield in the Redrock Creek watershed using AnnAGNPS and GIS

Sediment has been identified as a significant threat to water quality and channel clogging that in turn may lead to river flooding. With the increasing awareness of the impairment from sediment to water bodies in a watershed, identifying the locations of the major sediment sources and reducing the sediment through management practices will be important for an effective watershed management. The annualized agricultural non-point source pollution(AnnAGNPS) model and newly developed GIS interface for it were applied in a small agricultural watershed, Redrock Creek watershed, Kansas, in this pilot study for exploring the effectiveness of using this model as a management tool. The calibrated model appropriately simulated monthly runoff and sediment yield through the practices in this study and potentially suggested the ways of sediment reduction through evaluating the changes of land use and field operation in the model for the purpose of watershed management.

Crops Responses to Inter-Annual Climate Variability in Agroclimatic Zone of Sub-Saharan Africa

Climate variability has become a decisive factor for the crop yields in Sub-Saharan African countries. Inter-annual variability in rainfall has been the key climatic element that determines the success of agriculture in this region.From an analysis of recent rainfall conditions in West Africa,FAO(2001) concluded that a long-term change in rainfall has occurred in the semi-arid and sub-humid zones of West Africa.Thus,this study aims at assessing the vulnerability of crop yields to inter-annual variability in rainfall in sub-Saharan African countries taking Nigeria as a case study.A time series of the averaged value of the 12-Month Weighted Anomaly Standardized Precipita-

The Design of Stall-Regulated Wind Turbine Blade for a Maximum Annual Energy Output and Minimum Cost of Energy Based on a Specific Wind Statistic

The design of a stall-regulated wind turbine to achieve a maximum annual energy output is still a formidable task for engineers. The design could be carried out using an average wind speed together with a standard statistical distribution such as a Weibull with k = 2.0. In this study a more elaborated design will be attempted by also considering the statistical bias as a design criterion. The wind data used in this study were collected from three areas of the Lamtakong weather station in Nakhonratchasima Provice, the Khaokoh weather station in Phetchaboon and the Sirindhorn dam weather station in Ubonratchathani, Thailand. The objective is to design a best aerodynamic configurations for the blade (chord, twist and pitch) using the same airfoil as that of NREL Phase VI wind turbine. Such design is carried out at a design wind speed point. Wind turbine blades were optimized for both maximum annual energy production and minimum cost of energy using a method that take into account aerodynamic and structural considerations. The work will be carried out by the program “SuWiTStat” which was developed by the authors and based on BEM Theory (Blade Element Momentum). Another side issue is the credibility of the Weibull statistic in representing the real wind measurement. This study uses a regression analysis to determine this issue.

A PRELIMINARY STUDY ON THE VARIATION FEATURES OF GRAIN YIELD OF CHINA IN RECENT 40 YEARS

Based on grain yield data of China, the vanation features of grain yield in China in recent 40 years and their relationships with the associated factors were analyzed. Results show that the total grain yield increased gradually, and its interannual variation is influenced principally by unit area crop yield (about 70 percent in average). The influences of agricultural technology, social factors and weather conditions on thet area crop yield can be separated because of their unique variation trends and time scales. The influence of agricultural technology is in a smoothly and gradually incremental trend, and the influence of the social factors is oscillated with three waves in recent 40 years, and the influence of weather conditions is fiuctuated sharply from year to year. Their mean effects on the inter-annual variation of unit area crop yield are about 35 to 40 percent, 10 to 15 percent and 50 percent respectively. In the view point of predictions, the effects of weather conditions are much more important.

麦玉复种连作田土壤性状及周年产量对耕作与施肥的响应

保护性耕作与有机肥施用是黄土高原旱作农业区缓解生态脆弱问题的有效解决手段之一,合理的耕作与施肥措施对山西中部旱区实现麦玉一年两熟具有重要意义。以黄土高原旱作农田为研究对象,采用裂区试验设计,主区为3种耕作方式(深翻(DT)、深松(SS)、免耕(NT)),副区为4种施肥水平(不施肥对照(CK)、全量化肥(CF)、50%化肥+50%有机肥(OF)、全量有机肥(OM)),探究不同耕作与施肥方式下土壤容重、速效养分及麦玉周年产量的变化特征。结果表明,有机肥施用后SS、NT处理0~20 cm土壤容重较DT处理有所下降,其中小麦季SS+OF处理下耕层土壤容重为1.13 g/cm^(3),显著低于DT+OF处理。整个周年复种连作体系中,以NT+OM处理土壤质量含水量最高,较其他施肥处理平均升高7.88百分点;SS+OM处理下土壤的三相比更为理想,三相比偏离值偏低。3种耕作方式下,碱解氮与有效磷含量大小总体呈现OM>OF>CF>CK的趋势,速效钾含量与施肥方式存在极显著关系,其中CF处理下含量最高;玉米季增施有机肥较单施化肥显著提高了糯玉米鲜穗产量,但有机肥施用比例间的差异并不显著,SS+OM处理下麦玉周年产量最高,达19145 kg/hm 2。综上,该试验条件下,SS、NT耕作方式与有机肥施用结合可明显改善土壤的物理性状,碱解氮与有效磷含量也有一定程度的提升,其中,SS+OM处理更有利于黄土高原地区麦玉周年复种连作田产量的提升。

周年肥料运筹对双直播模式下棉油周年产量的影响

[目的]探索适合棉油双直播模式的氮、磷、钾肥周年运筹技术,为棉油双直播模式下棉花、油菜的增产增效提供依据。[方法]采用双因素裂区设计,因素A为周年施肥总量,分别设置低肥、中肥和高肥(A_(1)、A_(2)和A_(3))3个水平;因素B为棉花和油菜的施肥比例,分别设置1∶1、2∶3和3∶2(B_(1)、B_(2)和B_(3))3个水平。比较不同周年施肥水平下棉油双直播模式棉花与油菜的产量、产量构成因素及氮肥偏生产力。[结果]A_(2)水平下,A_(2)B_(2)处理的棉花产量与周年总产量最高;A_(3)水平下,A_(3)B_(2)处理的棉花产量与周年总产量最高;A_(2)B_(2)处理棉花产量显著高于A_(1)B_(2)与A_(3)B_(2)处理。A_(3)B_(1)处理油菜产量显著高于A_(1)B_(1)处理。A_(2)与A_(3)水平棉花单铃重除A_(3)B_(1)处理与A_(1)B_(3)处理差异不显著外,其他处理均显著高于A_(1)水平。棉花和油菜的氮肥偏生产力均随施肥量的递增而降低;A_(2)与A_(3)水平下,A_(2)B_(2)的棉花氮肥偏生产力最高。[结论]不同周年肥料运筹对双直播模式下棉油周年产量的增产效果存在差异,总体上以B_(2)水平的增产效果最佳。其中,A_(2)B_(2)处理(氮、磷和钾施肥量分别为360、180和270 kg·hm^(-2),棉油施肥比2∶3)在降低施肥水平、保持较高氮肥偏生产力的同时,可获得最高周年产量。

甲酰氨基嘧磺隆·甲基碘磺隆对夏玉米田杂草防除效果及其对产量的影响

设32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂14.4、22.8、31.2、45.6 g(a.i)/hm^(2)4个剂量,以30%甲酰氨基嘧磺隆水分散粒剂30 g(a.i)/hm^(2)为对照药剂,并设人工除草及空白对照,研究32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂对夏玉米田杂草防除效果及其对夏玉米产量的影响。在夏玉米播种后22 d、杂草2~6叶期进行茎叶喷药处理。于药后20、40、60 d分别监测杂草种群数量,同时取样分析杂草对养分的累积情况,并于夏玉米收获后进行测产。结果表明,施用32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂14.4~45.6 g(a.i)/hm^(2)对试验夏玉米田一年生杂草稗草[Echinochloa crusgalli(L.)Beauv]、马唐[Digitaria sanguinalis(L.)Scop]、旱莲草(Eclipta prostrata L.)、马齿苋(Portulaca oleracea L.)表现出较好的防除效果,药后60 d对稗草、马唐、旱莲草、马齿苋的株防效为79.82%~95.35%,对稗草、马唐、旱莲草、马齿苋的鲜重防效为81.75%~96.76%,与对照药剂30%甲酰氨基嘧磺隆水分散粒剂30 g(a.i)/hm^(2)对以上杂草的防效相当,供试药剂各处理对夏玉米的增产效果达20.70%~25.10%,显著优于空白对照和人工处理。32%甲酰氨基嘧磺隆·甲基碘磺隆钠盐水分散粒剂在使用过程中未发现药害,也未发现人畜中毒,对环境友好。

减氮增密对机插双季稻生物学特性及周年产量的影响

为推动稻草焚烧、高氮低密等传统稻作技术向资源节约型与环境友好型方向转型,在稻草还田下设置:常氮常密(T1)、常氮增密(T2)、减氮常密(T3)、减氮增密(T4)4种双季机插栽培模式,研究减氮增密对机插双季稻生物学特性及周年产量的影响。结果表明,稻草还田下,T4通过早、晚稻基肥减施总氮量的20%,增密27.3%,显著提高了成穗率、有效穗及结实率(P<0.05),早、晚稻成熟期的群体干物质重较T1仅分别减少3.3%、1.3%,早稻产量较T1增加1.6%,晚稻仅降低0.5%,周年产量增加0.4%。稻草还田下,早、晚稻T4的生育期较T1缩短2 d,有利于保障晚稻适龄机插;早、晚稻的个体SPAD及净光合速率(Pn)均随着施氮量的减少或密度的增加而降低,但群体叶面积衰减率、群体表观转运率、SPAD衰减率及Pn衰减率则表现出相反的规律,以T4最低。综上,稻草还田下减氮增密虽然抑制了机插双季稻的个体生长,但提高了抽穗期至成熟期群体光合物质的生产及转运能力,增加了产量库容量而获得高产,为双季稻区机插栽培技术的发展转型提供了一定的理论依据。

水氮运筹对小麦、玉米周年产量及水分利用的影响

在田间试验条件下,采用喷灌带进行灌水,研究不同氮肥基追比(A1:70%基施、30%追施;A2:60%基施、40%追施;小麦季施纯氮240 kg/hm^2,玉米季施纯氮270 kg/hm^2)和不同灌水量(B1:0次;B2:2次;B3:3次;小麦季和玉米季每次的灌水量均为450 m 3/hm^2)对小麦、玉米生长过程中土壤储水量、光合生理特性、产量和水分利用等的影响,以期明确小麦、玉米合理的氮肥追施比例和灌水量。结果表明,随灌水量增加,小麦抽穗期、灌浆期及玉米灌浆期、收获期土壤储水量总体呈增加趋势,小麦收获期土壤储水量呈降低趋势。小麦前期氮肥供应较多更有利于光合速率的提高,而适度干旱更有利于叶片水分利用效率的提高。随着灌水量的增加,小麦产量和水分利用效率均先增加后降低,而生物量和千粒质量均增加。不同处理中,小麦产量、水分利用效率和灌水利用率均以A1B2处理最高,分别为8207.8 kg/hm^2、26.7 kg/(mm·hm^2)和1.42 kg/m^3。对玉米而言,A2B2处理产量最高,A1B3处理水分利用效率和灌水利用率最高。小麦、玉米的周年耗水量表现为A1<A2;A2B2处理小麦、玉米周年产量最高,A1B3处理周年水分利用效率和灌水利用率最高。

耕作方式对华北冬小麦?夏玉米周年产量和水分利用的影响

在冬小麦季设置秸秆不还田翻耕（CT）、秸秆还田翻耕（CTS）、秸秆还田旋耕（RTS）和免耕秸秆覆盖（NTS）4种处理，研究耕作方式对华北小麦一玉米两熟区作物周年产量和水分利用的影响。结果表明：耕作方式对当季冬小麦产量和水分利用影响显著，对夏玉米产量和水分利用影响不大，但秸秆还田提高了夏玉米产量。RTS、CTS、CT3个处理小麦季产量差异不显著，而NTS由于有效穗数不足，产量显著低于其他处理；与CT相比，NTS周年产量平均减产5．13％，RTS增产2．69％，CTS增产2．33％。耕作方式对当季小麦土壤水分含量影响大，而对后茬夏玉米土壤水分含量的影响较小。NTS提高了小麦季土壤水分含量，增加了土壤储水量，与CT相比，0～60cm土壤储水量2010年和2011年分别增加39．07mm和26．65mm。从耗水构成来看，土壤水在冬小麦耗水中所占比例最大，其次为灌水和降水；而夏玉米耗水以降水为主，且降水中有一部分转化为土壤水储存起来。NTS提高了冬小麦季土壤储水量，降低了土壤水分的消耗，冬小麦季耗水最少。与CT相比，NTS小麦季平均节水22．40mm，周年耗水量也以NTS最少；但NTS冬小麦产量降低导致其小麦季和周年水分利用效率均最低。从作物周年产量和水分利用的角度来看，如何提高免耕秸秆覆盖小麦季产量，进而提高周年产量，发挥其节水优势，是该耕作模式在华北地区冬小麦一夏玉米两熟区推广应用亟需解决的关键问题。

不同葡萄品种设施环境适应性评价方法研究

为了确定评价不同葡萄品种设施环境适应性的方法,为葡萄设施栽培的品种选择提供理论依据。首先测定22个葡萄品种的光补偿点、表观量子效率、设施内外光合潜力差值、叶绿素总含量、叶绿素a和b含量、栅栏组织和海绵组织及叶片厚度、干比叶质量、CO2补偿点、羧化效率、蒸腾速率、暗呼吸速率和水分利用效率等生理指标,然后运用相关性分析,确定与连年丰产能力密切相关的生理指标,最后以与连年丰产能力密切相关的生理指标为基础数据,以连年丰产能力作为验证指标,对运用熵值法、Topsis方法和熵权Topsis方法等评价方法对葡萄的设施环境适应性得出的评价结果进行比较分析,筛选出快速有效的评价设施葡萄环境适应性的方法。结果表明:无核白鸡心和红香妃两葡萄品种可作为评价某葡萄品种是否适于设施栽培的参照品种。叶片光补偿点、叶绿素a含量、叶绿素总含量、设施内外光合潜力差值等4个生理指标与连年丰产系数显著相关,可作为评价设施葡萄环境适应性的基础数据。熵权(权重分别为光补偿点0.324、光合潜力差值0.250、叶绿素a含量0.227、叶绿素总含量0.199)Topsis综合评价法对设施葡萄环境适应性评价结果的排序与其连年丰产系数排序基本相同,Topsis综合评价法次之,熵值法最差。

耕作方式对冬小麦–夏玉米光合特性及周年产量形成的影响

【目的】作物的光合特性及干物质积累与转运是影响产量的重要因素。研究不同耕作方式对冬小麦–夏玉米光合特性、干物质积累转运及周年产量的影响,以期为冬小麦–夏玉米两熟地区选择适宜的耕作方式提供理论和实践依据。【方法】以黄淮海地区2003~2014年连续12年定位试验为平台,在秸秆还田前提下,试验设4种耕作方式:传统翻耕(PC)为对照、免耕(PZ)、深松(PS)和旋耕(PR)。对2014~2015季冬小麦和2015季夏玉米各项光合参数、干物质积累和产量进行了测定。【结果】长期不同耕作方式对冬小麦–夏玉米光合特性和周年产量影响显著,免耕、深松和旋耕处理的光合特性和周年产量均优于对照传统翻耕,依次为PS>PZ>PR>PC。PZ、PS和PR耕作方式显著提高了生育后期冬小麦和夏玉米功能叶的叶绿素含量、光合速率、气孔导度和蒸腾速率,其中冬小麦灌浆后期叶绿素含量分别提高了97.0%、121.1%和71.4%,光合速率分别提高了57.6%、71.6%和51.2%;夏玉米灌浆期叶绿素含量分别提高23.6%、28.1%和10.4%,光合速率分别提高18.6%、26.5%和19.2%,延缓了叶片衰老,使光合作用始终维持在较高水平。PZ、PS和PR处理冬小麦花后同化物对籽粒的贡献率分别达65.3%、67.8%和65.0%,夏玉米为66.3%、70.6%和63.4%,而对照处理(PC)冬小麦和夏玉米的贡献率仅为59.3%和60.9%。PZ和PS处理冬小麦和夏玉米的穗粒数和千粒重显著高于PC处理,穗数显著低于PC和PR。PZ、PS和PR可显著提高周年产量,分别提高15.4%、18.2%和11.0%。【结论】在黄淮海地区,采用长期秸秆还田下免耕、深松和旋耕均可提高冬小麦和夏玉米叶绿素含量和光合速率,提高胞间CO_2利用能力,降低非气孔限制,增强花后干物质积累能力,增加花后同化物对籽粒的贡献率,协调产量构成因素的关系,提高单季和周年产量,其中深松效果最佳,免耕次之。

青海高原不同海拔高度区小麦生长对气候变暖的响应

利用青海高原上两个不同海拔高度区农业气象观测站1980—2007年的观测资料,就低海拔地(民和)和高海拔地(诺木洪)的气候变化及其对春小麦生长发育和产量的影响差异进行研究。结果显示:28年来民和和诺木洪两站均存在变暖趋势,且高海拔地区的线性增暖幅度大于低海拔地区。春小麦对气候变暖的响应表现在低海拔地区播种期提前,成熟期基本没有变化,生育期延长,产量下降;高海拔地区播种期推迟,成熟期提前,生育期缩短,产量波动较大。春小麦生长期内日平均气温每升高1℃,高海拔地区春小麦生育期缩短11.7 d,而低海拔地区无显著变化。分蘖期是两地小麦生育时期变化的转折点,是环境与群体的"缓冲者"。

小麦-玉米轮作体系中秸秆还田方式对土壤肥力及作物产量的影响

【目的】探讨小麦-玉米轮作体系下不同秸秆还田方式对土壤肥力和作物产量的影响,旨在为促进小麦-玉米连续轮作区的农业可持续发展提供理论依据。【方法】在陕西关中地区,于2008-2010年采用2年4季的田间定位试验,以玉米秸秆不还田-小麦秸秆不还田为对照(CK),比较玉米秸秆覆盖还田-小麦秸秆高留茬还田(T-1)、玉米秸秆直接还田-小麦秸秆高留茬还田(T-2)、玉米秸秆直接还田-小麦秸秆直接还田(T-3)3种秸秆还田方式对土壤碳储量、养分含量及作物周年产量的影响。【结果】与CK相比,3种秸秆还田方式下耕层(0～20cm)土壤总有机碳储量(CT)、土壤活性有机碳储量(CL)、土壤碳库管理指数(CMI)及土壤全磷、硝态氮、速效钾含量和作物周年产量均增加。3种秸秆还田方式对CT、CL及CMI的影响表现为T-3>T-2>T-1;对作物周年产量的影响则表现为T-2>T-3>T-1;对土壤养分的影响无明显规律性,但是对速效钾含量的影响表现为T-2>T-3>T-1。【结论】综合考虑,在陕西关中小麦-玉米轮作体系中,玉米秸秆直接还田-小麦秸秆高留茬还田模式(T-2)是较优的耕作方式。