砾石覆盖量对夏玉米作物系数及水分利用效率的影响

为评价半湿润易旱地区砾石覆盖对土壤贮水量、作物生长与产量及水分利用效率的影响,利用杨凌地区夏玉米2014年实测数据及气象数据,基于Penman-Monteith公式计算了砾石不同覆盖量下全生育期内参考作物蒸发蒸腾量,并根据FAO推荐的分段单值平均法,计算夏玉米各生育期作物系数,以及砾石不同覆盖量下作物水分利用效率。结果表明:砾石覆盖的保水效果主要体现在作物生长初期,拔节期最大砾石覆盖处理0~200 cm土壤贮水量较对照增大12.8%,后期由于冠层覆盖影响其效果减弱;夏玉米全生育期作物系数与覆盖量呈线性关系;覆盖量越大,不同生育阶段的作物系数也相应增加;叶面积和株高与作物系数有着较好的回归关系,可以对生育期内的玉米蒸散量进行预报;砾石覆盖可以缩短夏玉米生育期的天数,最大可缩短19 d;砾石覆盖能促进作物生长,提高作物产量,且在该试验覆盖量范围内,覆盖量越大,增产增效越明显,随覆盖量增加,各处理分别较对照提高4.65%~38.17%;作物水分利用效率随覆盖量的增大分别较对照提高2.94%~32.99%。     

不同覆盖条件下冬小麦作物系数试验研究

试验共设置裸地(CK)、秸秆覆盖(JF)、地膜覆盖(DF)3个处理,基于冬小麦2013—2014年实测数据及气象数据,利用Penman-Monteith公式计算杨凌地区冬小麦全生育期内参考作物蒸发蒸腾量,利用农田水量平衡方程计算冬小麦全生育期实际作物蒸发蒸腾量,由此计算冬小麦各生育阶段的作物系数。结果表明:秸秆覆盖和地膜覆盖可以减少冬小麦全生育期的作物需水量,减少量分别为13.07 mm和17.86 mm;秸秆覆盖处理对水分比较敏感;作物系数在全生育期呈双峰变化,峰值出现在分蘖~越冬期和抽穗~灌浆期,其中CK为0.82和1.16,JF为0.89和1.05,DF为0.87和1.13;冬小麦作物系数与种植后天数和大于0℃积温呈现良好的四次多项式和二次多项式关系,其中JF与DF的相关系数均在0.88以上。     

播种期对农牧交错带马铃薯生长发育和产量形成及水分利用效率的影响

为了研究不同播种期对农牧交错带马铃薯生长发育和产量形成以及水分利用效率的影响,为农牧交错带马铃薯适期播种和高产栽培提供科学依据,采用随机区组排列设计,分析了超早播(4月28日)、早播(5月8日)、中播(5月18日)、晚播(5月28日)和超晚播(6月8日)五个播期下马铃薯生育期、形态指标、产量形成和水分利用效率的变化情况。结果表明:播种期对马铃薯生育期、株高和叶面积指数影响显著。随播期推迟,马铃薯生育期缩短,播期每推迟10 d,生育期平均缩短6 d,而生殖生长期在总生长期中的比例增加,超早播和超晚播处理下分别为45%和59%。超早播和早播马铃薯地上部干物质积累显著低于其余播期,不同播期处理薯块鲜重增长符合Logistic生长曲线,播期间马铃薯总产量、大薯产量和大薯率差异均达显著水平,其中中播、晚播和超晚播产量差异不显著,平均达21 593 kg/hm2,超早播和早播产量平均为15 181 kg/hm2。马铃薯水分利用效率随播期推迟增加,超早播为45.2 kg/(hm2.mm),超晚播为86.3 kg/(hm2.mm)。建议农牧交错带马铃薯适宜播种期安排在5月中下旬。     

太行山山前平原作物系数与降水年型关系探讨

利用中国科学院栾城农业生态系统试验站1995~2001气象数据和同期大型称重式蒸渗仪监测的小麦、玉米蒸散量,采用参考作物法探讨分析了小麦、玉米生长期作物系数与降水年型的关系。结果表明,不同降水年型下小麦生长期作物系数差异不明显,统计时段内小麦生育期作物系数平均值为0.90,丰水年玉米生长期作物系数偏高,平均值为1.2,而平水年与枯水年玉米生长期作物系数差异不明显,平均值为0.94。为准确估算作物需水量,实现精确灌溉,建议尽量采用长系列观测数据确定的不同降水年型的作物系数,尤其是在玉米生长期。     

渭北旱塬花椒灌溉效应研究

利用试验资料分析了不同水文年份、灌水时间、耗水量对花椒产量、水分利用效率(WUE)、品质及新生枝条生长量的影响,结果表明:在无灌溉条件下,降水量较多的年份花椒产量较高;干旱年份,在水量缺乏的情况下,应把有限的水量灌到果实膨大期,保证果实膨大期的花椒需水,不仅可以获得较高的产量及WUE,而且可以获得较好的花椒品质;枝条生长量与生长期水分供应有关,充足的水分供应,可保树势健旺。同时为便于花椒需水量计算,确定出花椒的作物系数为0.91。     

膜下滴灌条件下棉花年际需水量变化试验分析

为探索新疆准噶尔盆地南缘区膜下滴灌棉花年际需水量、水分生产率、作物系数、生长动态等变化,连续3年开展了灌溉试验,研究棉花耗水规律及气象因素对耗水规律的影响。结果表明:棉花生育期总耗水量随灌水量增加而增大,各处理(处理T1、T2、T3、T4分别为300、375、450、525 m~3·hm~(-2))耗水量差异显著,耗水量在343~625 mm之间;不同年份气象要素中气温对棉花生育阶段需水量影响最大;棉花皮棉产量与全生育期灌水量呈二次抛物线关系,水分生产率随灌水量的增加而降低,其值范围0.65~0.34 kg·m~(-3);不同时期棉花作物系数大小表现为:开花~吐絮现蕾~开花吐絮~收花出苗~现蕾播种~出苗,全生育期作物系数呈现单峰值变化,峰值出现在开花~吐絮期;生育期内棉花株高、叶面积指数和叶绿素均呈先增后减,最后保持平稳的趋势。不同处理棉花株高和叶面积指数与灌水量呈正比关系,随灌水量增大而增加,全生育期内株高和叶面积指数峰值出现在花铃期,叶绿素峰值出现在蕾期。     

科尔沁沙地青贮玉米蒸散量的估算与分析

为准确估算科尔沁沙地青贮玉米实际蒸散量的变化规律,选用ASCE Penman-Monteith(ASCE-PM)模型计算参考作物蒸散发(ET0);利用双作物系数模型模拟土壤含水率与对应实测值进行统计分析,根据均方根误差、一致性指数、平均绝对误差和Nash-Sutcliffe效率指数4个指标以及回归系数和决定性系数对双作物系数模型进行率定和验证,然后模拟青贮玉米的作物系数,与ASCE-PM模型结合后模拟青贮玉米的蒸散发、棵间土壤蒸发和作物蒸腾规律,并分析其影响因素。结果表明:双作物系数模型准确地模拟土壤含水率和棵间土壤蒸发的变化过程,率定各阶段基础作物系数为0.25、0.9和0.5。棵间土壤蒸发先由播种时峰值下降到较低水平,于收割前有所回升;蒸腾速率除刚出苗和收割前呈单峰变化外大部分时段呈双峰变化,日内变化规律大体为中午高,早晚低,自出苗之日起生长中期后半段处于较高水平,之后逐渐减弱。青贮玉米蒸散量与太阳辐射线性关系最为显著(R=0.643),与气温、空气湿度和风速的相关性依次次之。ASCE-PM模型空气动力项5 d尺度贡献率为27.94%~77.66%,且随风速同增减。综上所述,ASCE-PM模型结合双作物系数可较好估算科尔沁沙地青贮玉米的实际蒸散量,以及棵间土壤蒸发和作物蒸腾量。     

农牧交错带地区油葵适时播种气象条件分析

为了研究农牧交锗带不同播种期对油葵生长发育和产量形成以及水分利用效率的影响,为农牧交错带地区油葵适期播种和高产栽培提供科学依据,采用随机区组排列设计,分析了武川地区超早播(4月28日)、早播(5月8日)、中播(5月18日)、晚播(5月28日)和超晚播(6月8日)五个不同播期下油葵生育期、形态指标、产量形成及水分利用效率的变化情况。结果表明:播种期对油葵生育期、株高和叶面积指数影响显著。随播期推迟,油葵生育期缩短,播期每推迟10 d,生育期平均缩短9d,生殖生长期在总生长期中的比例增加,超晚播因积温不足无法正常成熟。晚播和超晚播叶面积指数显著高于其余播期,超晚播最大叶面积指数在五个播期中最高。中播地上部干物重和花盘干重显著高于其余播期,不同播期间花盘干重占地上部干物重的比例变化较大,中播最高为59％,超晚播最低为7％。超早播、早播和中播处理间产量和千粒重差异不显著,平均为2 583 kg·hm^-2和29.66 g,显著高于超晚播。水分利用效率随播期推迟减小,早播水分利用效率最高,为11.9 kg·hm^-2·mm^-1,超晚播水分利用效率最低,为5.5 kg·hm^-2·mm^-1,苗期适当干旱有利于油葵水分利用效率提高。建议农牧交错带油葵适宜播种期安排在5月中旬前后。     

大豆豆荚炭疽病中期预测模型的研制

根据杭州地区2006—2015年大豆豆荚炭疽病调查资料,建立了大豆豆荚炭疽病中期预测模型:y=-55.614 45+2.133 0x_2+22.252 67x_3+0.081 61x_1~2-4.974 81x_3~2(P≤0.01,R~2=0.723 4)。式中x_1是结荚后10 d的平均气温,x_2是结荚后5 d平均雨量,x_3是结荚后5 d雨日数,y是成熟期的病情指数。通过2010—2015年实际监测数据对模型进行验证,预测准确率为83.33%。本模型适合于杭州地区的对大豆豆荚炭疽病的预测。     

北疆春小麦蒸散规律及蒸散量估算研究

通过对2002～2003年北疆春小麦田试验数据的分析结果表明,北疆春小麦全生育期蒸散量在410～430mm左右,蒸散强度为4.11～4.14mm,蒸散量和蒸散强度均在抽穗～乳熟期达到最大,平均棵间蒸发占总蒸散量的比例为38.3%～42.0%。叶面积指数与蒸散强度关系极为密切,可用复合曲线方程来描述二者的关系。通过采用Penman-Montieth模式配合单值平均作物系数和水分胁迫系数估算农田蒸散量的方法,对当地春小麦田的日蒸散量进行估算,精确度检验结果表明该方法是切实可行的。     

基于作物水分盈亏指数的昆明水稻生长季干旱特征及成因分析

基于昆明站点1952—2013年逐日气象观测资料,根据联合国粮农组织1998年推荐的PenmanMonteith公式计算了昆明站近62 a来逐日的参考作物蒸腾量、水稻生育期需水量,利用Mann-Kendall趋势检验法研究作物需水量变化规律,同时根据水稻的水分亏缺指数(CWDI),采用通径分析方法研究各气象因子对水分亏缺指数的影响。结果表明:近62年来昆明地区平均旬需水量为32.55 mm;水稻生长季内干旱分布明显不均匀,随着生长季的推进,干旱级别从轻旱到重旱,干旱发生最严重时期是黄熟生育阶段,在整个水稻生长季内,水稻水分盈亏指数均值为38.07%,表明水稻处于重旱状态;在水稻生育期变异系数研究中,水分盈亏指数变异系数均较小,在返青、分蘖、拔节、抽穗、乳熟和黄熟六个阶段中,变异系数分别为1.8%、1.9%、1.3%、1.1%、0.8%、和0.8%,表明昆明地区近年干旱等级变化较小;影响水分盈亏指数最大正相关因素为日照,最大负相关因素为水汽压。     

新疆主要粮食作物滴灌条件下作物系数及水分生产率试验研究

通过3a小区试验,摸清新疆主要粮食作物在滴灌条件下作物系数和水分生产率的变化规律,为提高水资源利用效率、加强灌区用水管理、编制流域综合规划等项工作提供科学的试验数据和决策依据.采用小区试验方法,以小麦、早稻、玉米、土豆、谷子、大豆6种粮食作物为试验对象,设置灌水定额单因素4水平(300m3/hm2、375m3/hm2、...     

Effect of growth stages of chickpea on the genetic resistance of Ascochyta blight

Ascochyta blight (AB, Ascochyta rabiei (Pass.) Lab.) is one of the most important foliar disease of chickpea (Cicer arietinum L.), globally. Chickpea is attacked by AB at any growth stage in cool and humid weather depending on the inoculum availability. However, the disease epidemics are most prominent during the flowering and podding growth stages. The main objective of this study was to determine the effect of growth stages of chickpea on the genetic resistance of AB and use this information in a resistance breeding program. Two susceptible and two moderately resistant chickpea cultivars were spray inoculated at seedling (GS1), post-seedling (GS2), vegetative (GS3), flowering (GS4) and podding (GS5) growth stages with A. rabiei conidial suspension under controlled environment conditions. Irrespective of crop cultivars the incubation period (IP) was shorter in GS1, GS4 and GS5 and was significantly extended in GS2 and GS3. Symptom development was delayed significantly in moderately resistant cultivars. The AB severity 10 days after inoculation ranged between 7 and 9 on susceptible cultivars and 3 and 5 on moderately resistant cultivars. Further the correlation coefficient of disease severity between GS1, GS4 and GS5 was highly significant (r = 0.95) indicating that, evaluation for resistance to AB can be done at GS 1 (seedling stage), and or GS4 (flowering stage) to GS5 (podding stage) growth stages of chickpea. This supports the evaluation for AB resistance using 10-day-old-seedlings in controlled environment at ICRISAT and adult plant field screening at hot-spot locations in Dhaulakuan and Ludhiana in India.     

Impact of spatio-temporal simulations of rat damage on yield of rice (Oryza sativa L.) and implications for rodent pest management

Rodents often damage crops throughout the growing season, from germination to harvest, thus making it difficult to understand the cumulative effects of rodent damage for crops such as rice that are able to partially compensate for damage. Compensation can make it difficult to understand the impact of variable rodent damage in terms of when the damage occurs, its severity and thus when, whether and how rodent pests should be controlled. The compensatory responses of rice to simulated rat damage carried out at different growth stages and at different spatial levels of severity showed that higher yield was recorded during the wet season in comparison to the dry season. However, yield loss was observed during all cropping stages for all levels of simulated damage for wet and dry season crops, with significant compensation noted at the transplanting [14 days after sowing (DAS)] and vegetative (45 DAS) stages. Only damage at the maturity (110 DAS) stage resulted in significant reductions in rice crop yield. Seasonal differences suggest water availability was an important factor that perhaps enhanced rice production. The ability of rice to compensate for early rodent damage could potentially reduce a farmer's perception of damage. However, failing to control rodents at these earlier crop growth stages could lead to increased rodent populations at the time of maturity when compensatory effects are limited.     

Effect of soil management on soil erosion on sloping farmland during crop growth stages under a large-scale rainfall simulation experiment

Soil erosion on farmland is a critical environmental issue and the main source of sediment in the Yellow River, China. Thus, great efforts have been made to reduce runoff and soil loss by restoring vegetation on abandoned farmland. However, few studies have investigated runoff and soil loss from sloping farmland during crop growth season. The objective of this study was to investigate the effects of soil management on runoff and soil loss on sloping farmland during crop growth season. We tested different soybean growth stages (i.e., seedling stage (R1), initial blossoming stage (R2), full flowering stage (R3), pod bearing stage (R4), and initial filling stage (R5)) and soil management practice (one plot applied hoeing tillage (HT) before each rainfall event, whereas the other received no treatment (NH)) by applying simulated rainfall at an intensity of 80 mm/h. Results showed that runoff and soil loss both decreased and infiltration amount increased in successive soybean growth stages under both treatments. Compared with NH plot, there was less runoff and higher infiltration amount from HT plot. However, soil loss from HT plot was larger than that from NH plot in R1-R3, but lower in R4 and R5. In the early growth stages, hoeing tillage was effective for reducing runoff and enhancing rainfall infiltration. By contrast, hoeing tillage enhanced soil and water conservation during the late growth stages. The total soil loss from HT plot (509.0 g/m²) was 11.1% higher than that from NH plot (457.9 g/m²) in R1-R5. However, the infiltration amount from HT plot (313.9 mm) was 18.4% higher than that from NH plot (265.0 mm) and the total runoff volume from HT plot was 49.7% less than that from NH plot. These results indicated that crop vegetation can also act as a type of vegetation cover and play an important role on sloping farmland. Thus, adopting rational soil management in crop planting on sloping farmland can effectively reduce runoff and soil loss, as well as maximize rainwater infiltration during crop growth period.     

新疆北部膜下滴灌棉田的蒸散特征

利用乌兰乌苏农业气象试验站2009年6月至2010年6月的涡度相关资料,分析新疆北部膜下滴灌棉田不同生育期的蒸散变化特征及蒸散量。结果表明：各生育期蒸散量与净辐射的日变化表现出很高的一致性,午间蒸散强度最大;播种-出苗期、苗期和吐絮期蒸散量主要受净辐射控制,蕾期与花铃期蒸散量主要受叶面积指数控制;在现行膜下滴灌灌溉制度下（年灌溉定额340~390 mm）,除吐絮期外,其他生育期土壤含水量均可以满足棉田蒸散耗水;播种-出苗期、苗期、蕾期、花铃期和吐絮期平均日蒸散量分别为1.8 mm/d,1.7 mm/d,3.7 mm/d,3.8 mm/d和1.2 mm/d,全生育期蒸散量为514.3 mm。     

Development of ascochyta blight (Ascochyta rabiei) in chickpea as affected by host resistance and plant age

Ascochyta blight caused by Ascochyta rabiei, is the most destructive disease in many chickpea growing countries. Disease development varies with the growth stage and host resistance. Hence, disease development was studied in cvs ICCX 810800 (resistant), ICCV 90201 (moderately resistant), C 235 (moderately susceptible), ICCV 96029 and Pb 7 (susceptible) under controlled environment (ICRISAT, Patencheru) and field conditions (Dhaulakuan, Himachal Pradesh) at seedling, post-seedling, vegetative, flowering and podding stages. Under controlled environment, the incubation period and terminal disease reaction (TDR) did not vary significantly at different growth stages against virulent isolate AB 4. Cultivars ICCX 810800, ICCV 90201 and C 235 showed a significantly longer incubation period than the susceptible cv. Pb 7. Cultivar ICCX 810800 showed slow disease progress and the least TDR. Field experiments were conducted during the 2003–2004 and 2004–2005 growing seasons. During 2003–2004, TDR was higher in plants inoculated at podding and the flowering stage and the lowest disease reaction was recorded in ICCX 810800. A severe epidemic during 2004–2005 was attributed to the favourable temperature, humidity and well distributed high rainfall. TDR did not differ significantly at any of the growth stages in susceptible cvs ICCV 96029 and Pb 7. With respect to seeding date and cultivar, the highest yield was recorded in the early-sown crop (1,276.7 kg ha⁻¹) and in ICCV 90201 (1,799.3 kg ha⁻¹), respectively. The yields were greatly reduced in all the cultivars during 2004–2005 and the highest yield was recorded in ICCX 810800 (524.7 kg ha⁻¹). Integrated disease management using resistant cultivars, optimum sowing period and foliar application of fungicides will improve chickpea production. The experiment under controlled environment and field conditions (during the epidemic year) showed a similar disease development.     

干旱区棉花水分胁迫指数对滴灌均匀系数和灌水量的响应

为了修订和完善滴灌均匀系数的设计与评价标准,在新疆干旱区研究了滴灌均匀系数和灌水量对作物水分胁迫指数（CWSI）的影响。供试作物为棉花,试验中滴灌均匀系数（C_u）设置0.65（C1）、0.78（C2）和0.94（C3）三个水平,灌水量设置充分灌水量的50%、75%和100%三个水平。结果表明：棉花冠层温度和CWSI表现出随灌水量增加而降低的趋势;冠层温度和CWSI均匀系数的变化范围分别为0.91～0.98和0.65～0.91,均随滴灌均匀系数增加而增大;灌水量对冠层温度和CWSI均值的影响达到极显著水平（α=0.01）,滴灌均匀系数对冠层温度和CWSI均匀系数的影响达到显著水平（α=0.05）或极显著水平。CWSI与皮棉产量呈显著或极显著的负相关关系;滴灌均匀系数越低,水分亏缺引起的减产幅度越小。