2010年中国农作物净初级生产力及其空间分布格局

采用2011-2012年全国实测水稻、小麦、玉米、大豆、油菜、棉花6种作物的生物量获得的干燥系数（DC）、收获指数（HI）和根冠比（R/S）,结合2010年以县为单位的农业统计数据估算了2010年中国农作物产生的净初级生产力（NPP）。2010年中国农作物产生的NPP为596 Tg C,其中地上NPP为517 Tg C,地下NPP为80 Tg C。NPP空间分布不平衡,主要集中在东北的松嫩三江平原、黄淮海平原、长江中下游平原、西南的四川盆地和华南的珠江流域。单位面积农作物产生的NPP介于9-2094 g C m^-2 a^-1之间,平均密度为519 g C m^-2 a^-1。NPP密度（NPPD）较高的地区主要分布在中国的东部的湿润、半湿润地区以及内陆灌溉条件较好的地区。9个农业区中,黄淮海区农作物产生的NPP最多,东北区NPPD最高,青藏区农作物NPPD最低,产生的NPP也最少。作物种植面积能解释98%农业区之间NPP差异。通过对每个区域内县域NPPD与气候因子和化肥因子做相关分析,发现化肥施用量、日照时数、气温和降水均对NPPD的空间分异有影响,但是9个区域的主导因素不同。     

雅砻江中游厚唇裸重唇鱼种群结构与生长特性

于2020年10月至2021年3月在四川省甘孜藏族自治州雅砻江江段（雅江县至新龙县）采集厚唇裸重唇鱼（Gymnodiptychus pachycheilus）样本189尾,用以研究雅砻江中游厚唇裸重唇鱼的种群结构与生长特性,分析其野生资源现状、影响因素及保护对策。结果显示雅砻江中游厚唇裸重唇鱼调查种群由3-9龄组成,其中优势年龄组为4-6龄,占样本总数的87.83%;种群平均体长和体重分别为264.1 mm和250.5 g,雌雄性比为1.48：1,雌性和雄性最小性成熟个体年龄均为4龄,对应体长分别为202.0 mm和220.0 mm,对应体重分别为105.0 g和133.0 g;种群的平均肥满度为1.22,体长（L）与体重（W）关系式为W=5.00×10^-6L^3.146（R²=0.948,n=189）,属于匀速生长类型;种群体长和体重的Von Bertalanffy生长方程分别为L_t=727.5[1-e^{-0.097（t-0.508）}],W_t=5224.9[1-e^{-0.097（t-0.508）}]^3.146;生长拐点年龄为12.4龄,对应的体长和体重分别为505.2 mm和1568.3 g。研究表明目前雅砻江中游厚唇裸重唇鱼表现出年龄结构趋于低龄化,体型趋于小型化的种群结构特点,且具有自然寿命较长、生长缓慢、渐近体长较大等生长特性,加之雅砻江饵料基础和水文条件较差等因素,推测雅砻江中游厚唇裸重唇鱼所具备的种群增长潜力较低,其野生资源的自然恢复面临挑战。因此,应尽快开展雅砻江流域厚唇裸重唇鱼野生资源的保护工作。     

麦秸与稻秸浸提液对油菜及2种靶标杂草种苗生长影响的差异性研究

采用室内培养皿生物测定的方法,测试不同质量浓度（0、0.02、0.03、0.05、0.08、0.10 g·mL^-1）麦秸、稻秸浸提液对油菜及油菜田2种常见靶标杂草野燕麦（Avena fatua Linn）、播娘蒿 ［Descurainia sophia（L.）Schur］种子萌发及幼苗生长的影响。结果表明,在供试质量浓度下,麦秸与稻秸浸提液对3种受体材料种苗生长的影响存在显著差异,二者对油菜种苗生长安全的最高质量浓度分别为0.08 g·mL^-1和0.05 g·mL^-1,可以用来开发研制油菜田肥料;在对油菜安全的质量浓度下,麦秸浸提液对野燕麦种苗生长无抑制作用;而稻秸浸提液对野燕麦种苗生长的抑制作用明显,可以用来开发研制油菜田防除野燕麦的生物抑草肥;在油菜的安全的质量浓度下,麦秸、稻秸浸提液对播娘蒿种苗生长均有很强的抑制作用,且麦秸的抑制作用强于稻秸,具有开发研制油菜田治理播娘蒿的生物抑草肥料的应用前景。     

不同作物秸秆还田对设施黄瓜生长及光合特性的影响

以黄瓜品种‘津优4号’和经过1年腐熟的花生秸秆、玉米秸秆和稻壳为试验材料,研究不同作物秸秆还田对黄瓜生长、营养吸收及光合特性的影响。结果显示:（1）与对照相比,不同作物秸秆还田不仅显著增加了黄瓜植株的根系活力和叶片硝酸还原酶活性,而且提高了黄瓜叶片的叶绿素含量、PSⅡ最大光化学效率（F^v/F^m）和实际光化学效率（Ф^PSⅡ）及光合速率,使得黄瓜叶片对光能的利用效率增加,净光合速率显著增强。（2）不同秸秆还田还促进了黄瓜的株高、茎粗、地上部和根系的干鲜重增加,显著提高了黄瓜产量。（3）玉米秸秆还田效果最好,其黄瓜产量（5 765.74 g·m^-2）较对照显著提高了43.8%,其次为花生秸秆还田,稻壳还田效果稍差。研究表明,秸秆还田促进了黄瓜植株根系吸收能力,显著增强了叶片的氮代谢、光能利用效率、净光合速率,从而促进了黄瓜植株的生长发育,提高了产量,并以玉米秸秆还田效果最佳。     

基于DSSAT模型对豫北地区夏玉米灌溉制度的优化模拟

合理的灌溉制度是提高农业水资源利用效率、保证夏玉米高产稳产的前提。采用农业技术转化决策系统(DSSAT,Decision Support System for Agrotechno1ogy Transfer)探究了河南省北部地区夏玉米不同降水年型下的最优灌溉制度。经过参数的校正和验证,归一化均方根误差(nRMSE)、均方根误差(RMSE)和一致性指数(d)均表现出模拟值与实测值的吻合度很好,DSSAT-maize模型可以准确模拟夏玉米物候期、地上部分生物量、产量和土壤水分状况。然后基于模型模拟了不同灌溉处理下的夏玉米生产潜力,从而评估夏玉米缺水量,并对比分析不同生育时期灌水对产量的影响确定最优灌溉时期,综合考虑产量和水分利用效率确定最优灌溉制度。结果表明:夏玉米生长季的缺水量年际间差异显著,多年平均值为38.91 mm,波动范围为0—193.03 mm。在丰水年,不需要灌溉;在平水年,开花期灌水30 mm;在枯水年,开花期和灌浆期灌水50 mm;在特别干旱年,苗期、拔节期和开花期至少灌水180 mm。优化的灌溉制度下丰水年、平水年和枯水年的WUE达到最高且产量分别占其最高产量的100%、99.72%和97.89%,实现了作物高产节水协同提高的目标。     

不同水分条件下杨树-玉米复合系统凋落物分解特性

为探讨水分变化对农林复合生态系统凋落物分解特性的影响,以河西走廊杨树（Populus）-玉米（Zea mays）凋落物为研究对象,设置正常水分（9200 m³/hm²,对照）,轻度干旱胁迫（减少15%,7800 m³/hm²）,中度干旱胁迫（减少30%,6400 m³/hm²）3种不同水分处理条件,采用分解袋法研究了不同水分条件下杨树叶和玉米秸秆的质量残留率、分解速率和养分含量变化特征。结果表明：（1）随着干旱胁迫的加剧,两种凋落物的质量残留率均增加,而分解速率降低。经过164 d的分解后,杨树叶和玉米秸秆的质量残留率分别为70.43%-77.49%、63.55%-68.29%。分析表明：水分和时间对各类型凋落物的质量残留率均有极显著的影响（P<0.001）,但二者的交互作用不显著（P>0.05）;干旱胁迫显著降低了玉米秸秆的分解速率,但杨树叶的分解速率却只是在中度干旱胁迫下显著降低（P<0.05）。对于不同类型凋落物而言,分解速率表现为玉米秸秆>杨树叶。（2）两种类型凋落物的氮（N）残留率在分解过程中表现为降低的趋势,但随着干旱程度的加大,N的残留率增加,表明水分抑制了N的释放过程。分解164d后,同一类型凋落物不同水分条件下的N残留率均存在显著差异。对于同一水分条件下不同凋落物而言,玉米秸秆的N残留率最低,而杨树叶最高。总的来说,水分降低对干旱区农林复合系统内凋落物的分解和氮元素含量具有显著的抑制作用。     

Cr6+对人工湿地薏苡光合特性和微量元素吸收的影响

为深入了解Cr⁶⁺胁迫对人工湿地植物薏苡光合特性和微量元素吸收的影响,该文通过构筑微型垂直流薏苡(Coix lacryma-jobi)人工湿地,采用1/2 Hoagland''s营养液配制的含0、5、20、40 mg·L^-1 Cr⁶⁺废水为灌溉用水,研究铬胁迫对人工湿地植物生长、光合特性、抗氧化酶活性和微量元素吸收等的影响。结果表明:(1)低浓度(5 mg·L^-1)Cr⁶⁺对薏苡的株高、茎粗和分蘖影响不显著,高浓度(20、40 mg·L^-1)Cr⁶⁺则显著抑制薏苡的生长。(2)低浓度Cr⁶⁺处理下,薏苡叶片净光合速率(P_n)、气孔导度(G_s)和蒸腾速率(T_r)有不同程度的提高,提高幅度分别为6.8%～54.8%、13.0%～40.3%和9.1%～36.4%。高浓度Cr⁶⁺处理下,叶片P_n、G_s、T_r等指标显著下降,但叶片胞间CO₂浓度(C_i)则显著提高。(3)薏苡叶片超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均随着处理时间的延长而提高; 低浓度Cr⁶⁺处理下,薏苡叶片SOD活性与对照差异不大,高浓度Cr⁶⁺处理下,SOD活性受到显著抑制。薏苡叶片POD活性和丙二醛(MDA)含量均随Cr⁶⁺处理浓度的提高而提高。(4)高浓度Cr⁶⁺处理显著抑制根系、茎、叶对Cu 、Fe、Mn和Zn的吸收。(5)5、20 mg·L^-1 Cr⁶⁺处理下,人工湿地对Cr⁶⁺去除率最高可达99%,40 mg·L^-1 Cr⁶⁺处理下最高则为86%。综上认为,Cr⁶⁺胁迫导致Fe、Mn、Zn和Cu等元素吸收量显著下降,光合受阻,抗氧化系统受损,植物生长受到抑制,最终导致人工湿地处理含Cr⁶⁺废水的能力下降。     

DSSAT模型对吉林省梨树县部分主要作物的适用性

明确DSSAT作物模型对东北地区主要作物生长发育和产量模拟适用性,对进一步开展东北地区DSSAT模型应用推广研究进而保障粮食安全具有重要意义。以吉林省梨树县春小麦、大豆、谷子和马铃薯4种主要作物为研究对象,利用3年田间试验资料对DSSAT模型进行了系统评价。结果表明：DSSAT模型中春小麦、大豆、谷子和马铃薯的生育期、叶面积指数、地上生物量、茎部生物量、叶片生物量和产量的模拟值与实测值的决定系数分别为0.94～0.99、0.92～0.99、0.96～0.99和0.97～0.98,归一化均方根误差分别为12.21%～26.01%、1.67%～33.24%、1%～15.34%和3.2%～28.08%,D值均在0.994以上;其中,春小麦生育期及产量拟合程度最高,其次为叶面积指数;大豆及谷子产量及叶面积指数拟合程度最高,其次为生育期;马铃薯生育期及产量拟合程度最高,其次为叶面积指数;而作物叶面积指数、叶片生物量、茎部生物量及地上部总生物量的生长动态过程模拟结果显示,春小麦、大豆、谷子和马铃薯的决定系数均在0.84以上,归一化均方根误差分别为24.5%～38.2%、28.7%～47.4%、9....     

双季稻田种植不同冬季作物对甲烷和氧化亚氮排放的影响

研究双季稻收获后填闲种植不同冬季作物在其生长季节内CH₄和N₂O的排放特征,对合理利用冬闲稻田,发展冬季作物生产及合理评价不同种植模式具有重要意义。采用静态箱-气相色谱法对冬季免耕直播黑麦草、紫云英、油菜以及翻耕移栽油菜和冬闲的双季稻田中甲烷(CH₄)和氧化亚氮(N₂O)排放进行了分析。结果表明:在冬季作物生长期,CH₄、N₂O平均排放通量和总排放量均表现为翻耕移栽油菜＞免耕直播黑麦草＞免耕直播油菜＞免耕直播紫云英＞冬闲。不同冬季作物稻田CH₄和N₂O总排放量与对照(冬闲)的差异均达到极显著水平(P<0.01);翻耕移栽油菜的双季稻田中CH₄和N₂O排放量最高,分别达2.989 g/m²和0.719 g/m²。翻耕移栽油菜稻田的CH₄和N₂O温室效应总和也最大,为2893.92 kg CO₂/hm²;免耕直播黑麦草和免耕直播油菜处理次之,而免耕直播紫云英处理最低。种植不同冬季作物促进了稻田生态系统CH₄和N₂O的排放。     

短期NaCl胁迫对不同小麦品种幼苗K+吸收和Na+、K+积累的影响

为研究盐胁迫下小麦幼苗生长及Na⁺、K⁺的吸收和积累规律,以中国春、洲元9369和长武134等3种耐盐性不同小麦品种为材料,采用非损伤微测技术检测盐胁迫2 d后的根系K⁺离子流变化,并对植株体内的Na⁺、K⁺含量进行测定。结果表明:短期(2d)盐胁迫对小麦生长有抑制作用,且对根系的抑制大于地上部,耐盐品种下降幅度小于盐敏感品种。盐胁迫下,小麦根际的 K⁺大量外流,盐敏感品种中国春K⁺流速显著高于耐盐品种长武134,最高可达15倍。小麦幼苗地上部分和根系均表现为Na⁺积累增加,K⁺积累减少,Na⁺/K⁺比随盐浓度增加而上升。中国春限Na⁺能力显著低于长武134,Na⁺/K⁺则显著高于长武134。综上所述,盐胁迫下造成小麦组织器官中Na⁺/K⁺比上升的主要原因是根系K⁺大量外流和Na⁺的过量积累,耐盐性不同的小麦品种间差异显著,并认为根系对K⁺的保有能力可能是作物耐盐性评价的一个重要指标。     

黑河中游春小麦需水量空间分布

合理估计春小麦的需水量(ET_c)是进行干旱区水资源配置的有效方法,利用黑河中游14个气象站1970-2009年的逐日气象资料,应用Penman-Monteith公式估算各站点的参考作物蒸散量,并根据春小麦生长期的作物系数,在地理信息系统(GIS)技术支持下得出黑河中游春小麦需水量的空间分布及变化趋势。结果表明:1970-2009年黑河中游春小麦作物需水量整体分布具有从南向北递增的趋势,全生长期需水量在573-781 mm之间;高台、张掖、临泽、民乐、山丹、酒泉的春小麦需水量分别为731.26、686.88、598.24、728.89、719.77、713.59 mm,其中生长中期需水量最大,分别占全生长期的51.67%、51.11%、50.96%、51.24%、50.83%和50.77%;日平均气温、日照时数、风速、降水量、最小相对湿度和各因子的影响力由大到小分别占总影响力的57.29%、26.92%、15.15%、1.41%和0.78%。     

气候变化背景下中国南方地区季节性干旱特征与适应Ⅵ.防旱避灾种植模式优化布局

南方地区是我国重要的农业种植区,季节性干旱严重影响该地区的农业生产.本文基于南方地区不同干旱分区中选取的13个典型地区1981-2007年气象资料和作物生育期、产量等资料,依据各地逐年降水量将其分为干旱年、正常年和丰水年3种不同降水年型,利用作物水分临界期需水量与降水量的耦合度、气象产量、单位面积产值以及全生育期的水分利用效率和降水量5个指标,对典型地区种植模式的综合效益进行评价,得到南方不同区域不同降水年型下的优化种植模式.结果表明: 半干旱区在干旱年型下,宜采取2种抗旱种植模式：马铃-玉米-甘薯和冬小麦-中稻-甘薯.半湿润区在干旱年型下,种植模式以冬小麦-中稻-甘薯最优,油菜-中稻-甘薯次之.在温润区(即典型的季节性干旱区),江南地区在3种年型下均以马铃薯-双季稻最优;西南地区宜搭配抗旱作物进行三熟制种植,如冬小麦-中稻-甘薯、冬小麦-玉米-甘薯、马铃薯-双季稻等.从最大程度利用水热资源角度考虑,三熟种植模式最优,以水旱轮作为主,丰水年型宜搭配水稻.     

The implication of irrigation in climate change impact assessment: a European‐wide study

This study evaluates the impacts of projected climate change on irrigation requirements and yields of six crops (winter wheat, winter barley, rapeseed, grain maize, potato, and sugar beet) in Europe. Furthermore, the uncertainty deriving from consideration of irrigation, CO₂ effects on crop growth and transpiration, and different climate change scenarios in climate change impact assessments is quantified. Net irrigation requirement (NIR) and yields of the six crops were simulated for a baseline (1982–2006) and three SRES scenarios (B1, B2 and A1B, 2040–2064) under rainfed and irrigated conditions, using a process‐based crop model, SIMPLACE . We found that projected climate change decreased NIR of the three winter crops in northern Europe (up to 81 mm), but increased NIR of all the six crops in the Mediterranean regions (up to 182 mm yr^?1). Climate change increased yields of the three winter crops and sugar beet in middle and northern regions (up to 36%), but decreased their yields in Mediterranean countries (up to 81%). Consideration of CO₂ effects can alter the direction of change in NIR for irrigated crops in the south and of yields for C3 crops in central and northern Europe. Constraining the model to rainfed conditions for spring crops led to a negative bias in simulating climate change impacts on yields (up to 44%), which was proportional to the irrigation ratio of the simulation unit. Impacts on NIR and yields were generally consistent across the three SRES scenarios for the majority of regions in Europe. We conclude that due to the magnitude of irrigation and CO₂ effects, they should both be considered in the simulation of climate change impacts on crop production and water availability, particularly for crops and regions with a high proportion of irrigated crop area.     

Enhancing water use efficiency and grain yield of wheat by optimizing irrigation supply in arid and semi-arid regions of Pakistan

The lack of good irrigation practices and policy reforms in Pakistan triggers major threats to the water and food security of the country. In the future, irrigation will happen under the scarcity of water, as inadequate irrigation water becomes the requirement rather than the exception. The precise application of water with irrigation management is therefore needed. This research evaluated the wheat grain yield and water use efficiency (WUE) under limited irrigation practices in arid and semi-arid regions of Pakistan. DSSAT was used to simulate yield and assess alternative irrigation scheduling based on different levels of irrigation starting from the actual irrigation level up to 65% less irrigation. The findings demonstrated that different levels of irrigation had substantial effects on wheat grain yield and total water consumption. After comparing the different irrigation levels, the high amount of actual irrigation level in semi-arid sites decreased the WUE and wheat grain yield. However, the arid site (Site-1) showed the highest wheat grain yield 2394 kg ha^?1 and WUE 5.9 kg^?3 on actual irrigation (T₁), and with the reduction of water, wheat grain yield decreased continuously. The optimal irrigation level was attained on semi-arid (site-2) with 50% (T₁₁) less water where the wheat grain yield and WUE were 1925 kg ha^?1 and 4.47 kg^?3 respectively. The best irrigation level was acquired with 40% less water (T₉) on semi-arid (site-3), where wheat grain yield and WUE were 1925 kg ha^?1 and 4.57 kg^?3, respectively. The results demonstrated that reducing the irrigation levels could promote the growth of wheat, resulting in an improved WUE. In crux, significant potential for further improving the efficiency of agricultural water usage in the region relies on effective soil moisture management and efficient use of water.     

冬季作物种植对双季稻根系酶活性及形态指标的影响

基于湖南长沙7a定位试验,以冬闲为对照,研究了冬种马铃薯、紫云英及油菜为前茬作物对早、晚稻根系酶活性、形态指标及产量的影响.结果表明,与冬闲相比,冬种作物后早、晚稻根系丙二醛(MDA)含量增加,但其根系的活性氧清除能力更强(SOD、POD和CAT活性高),能够在一定程度上缓解膜脂过氧化作用带来的伤害;冬种不同作物对早晚稻根系形态的影响表现不一.冬种马铃薯和紫云英处理在早稻生育后期的根系优势明显,并能在一定程度上促进晚稻根系生长,双季稻总产量较对照分别增加6.29％和7.76％,而冬种油菜抑制了晚稻根系生长,导致晚稻产量及双季稻总产分别降低6.31％和1.96％;相关性分析表明,灌浆期较高的根长、根数、根体积和根表面积是冬种作物改善双季稻产量的主要原因.综合来看,冬种马铃薯和紫云英对于促进双季稻根系生长,提高稻谷产量具有重要作用,而冬种油菜则不利于提高双季稻的稻谷生产力.     

气候变化背景下松嫩平原玉米灌溉需水量估算及预测

开展农作物需水规律研究对于干旱半干旱区域旱作物节水灌溉和水分管理实践具有重要意义。以松嫩平原玉米为研究对象,研究玉米生育期需水量规律及灌溉需水量。结果表明:(1)历史时期和未来气候变化情景下,松嫩平原玉米全生育期和L~(mid)时段灌溉需水量等值线沿西南—东北方向递减,其中全生育期和L~(mid)时段2000s灌溉需水量临界等势线(灌溉需水量为0的等势线)分别比1970s北移70.2km和53.4km,全生育期和L~(mid)时段2040s灌溉需水量临界等势线分别比2010s北移30.9km和55.2km。(2)历史时期和气候变化情景下玉米全生育期灌溉需水量随年代呈波动增加趋势,其中前者以29.1mm/(10a)速度增加,后者以17.5mm/(10a)速度增加。(3)未来温度和降雨量变化对玉米需水量的贡献率为波动上升趋势,与1970s相比,2000s温度和降雨量变化对玉米需水量的贡献率为22.1%,增加6.8亿m~3灌溉水量;2040s温度和降雨量变化对玉米需水量的贡献率为38.3%,增加12.6亿m~3灌溉水量。     

Effects of varying levels and frequencies of irrigation on growth,yield, nutrient uptake and water use efficiency of maize and cowpeas on a sandy loam ultisol

Summary A greenhouse study was carried out on an Nsukka sandy loam Ultisol having low soil moisture retention capacity to investigate the soil moisture regime and irrigation frequency required for optimum growth, yield, nutrient uptake and water use efficiency of maize (Zea mays L.) and cowpeas (Vigna unguiculata L. Walp). Four irrigation amounts (400 cm³, 300 cm³, 200 cm³ and 100 cm³ equivalent to 100, 75, 50 and 25% of field capacity, respectively) and four irrigation frequencies (daily, 2-day, 3-day and 4-day intervals) were tested in a factorial randomized design with three replications.Growth of maize was best when irrigation with water equivalent to 75% field capacity at daily interval but the optimum yields and nutrient uptake of both crops as well as cowpea nodulation were obtained when irrigating with water equivalent to 100% field capacity at daily or 2-day interval. The optimum water use efficiency was, however, achieved when irragating with amount equivalent to 100% field capacity at a 2-day interval. Irrigation with water equivalent to 50 or 25% field capacity at any interval resulted in various degrees of moisture stress which manifested in poor crop performance.     

基于降水利用比较分析的四川省种植制度优化

比较分析四川8个农业生态区典型站点及其主要种植模式的降水盈亏产量降低率、产量降低率风险指数、降水利用效率和降水经济效率。结果表明:(1)四川省不同区域、不同种植模式、不同作物及其不同生育阶段基于降水盈亏的产量降低率多年均值差异较大。区域分布上,雅安最低,仅23％,攀西最高,达50％以上,其余地区30％-40％;种植制度上,麦-玉-苕等旱三熟低于麦-稻等水旱轮作两熟制;作物种类上,冬小麦、冬油菜、秋播马铃薯等作物普遍高于水稻、玉米、棉花、红薯和大豆作物;生育阶段上,冬小麦、冬油菜、秋播马铃薯作物开花前后普遍较高,各种作物生育末期较低。(2)基于自然降水,攀西地区遭遇旱灾的风险极大,麦-玉-苕等旱三熟的产量降低率风险指数相对较小;雅安等盆地内部多数区域由于阶段性降水过多引起湿害偏重,导致麦-稻等水旱轮作两熟制略优于旱三熟。基于降水利用效率和降水经济效率,各地比较一致,较优的种植制度首先是麦(油、薯)-稻两熟制,其次才是麦(油)-玉-苕(豆)旱三熟。(3)综合旱涝灾害风险、降水利用效率和降水经济效率,以及复杂地形等因素,有较好灌溉条件的农田应以麦(油、薯)-稻水旱轮作两熟制为主,而无水源保障的旱地则以麦(油)-玉-苕(豆)旱三熟为主。     

Responses of photosynthetic rates and yield/quality of main crops to irrigation and manure application in the black soil area of Northeast China

Soil nutrients and water have long been recognized as the main determining factors influencing agricultural productivity in rain-fed agriculture. Manure application and irrigation can increase crop yield when nutrients and water are deficient. Often effects of water and nutrients are closely related and can not be easily separated in actual production. Three years of experiment were conducted in northern part of black soil area of Northeast China to investigate the responses of photosynthetic rates and yield/quality of main crops, wheat (Triticum aestivum L.), maize (May zeas L.), soybean (Glycine max L. Merr.) to irrigation and manure application. Irrigation and manure application had no effects on photosynthetic patterns during reproductive development in crops, maximum photosynthetic rates were achieved by irrigation, and manure application maintained relatively higher photosynthetic rates after the peak. On average, higher photosynthetic rates with irrigation may contribute to higher yield in soybean but not in maize and wheat. Responses of crop yield and quality to manure application and irrigation varied in the crops. Soybean yield and quality was very sensitive to irrigation and manure application. The greater supply of nutrients with sufficient water, the higher the yield. However, the high-yield of soybean achieved was accompanied with a decline of seed protein content. Maize yield mainly depended on nutrients used not the water supply, irrigation resulted in higher water content in the seed of maize and lower grain protein content in wheat at harvest, which is detrimental to seed storage in maize and processing quality in wheat. In the northern part of black soil area in Northeast China, the management of manure is critical to improve crop production, the optimum management for maize and wheat production was to apply chemical fertilizer and manure without irrigation, but for soybean was to apply fertilizer and manure with irrigation.