限根栽培对设施大樱桃幼树控冠效果的研究

为解决设施大樱桃树冠生长旺盛、结果晚、产量低的问题,采用槽式、箱筐式以及结合根系断根修剪的限根技术,研究了不同限根方式对设施大樱桃幼树的控冠效果。结果表明,环形断根抑制株高和新梢生长的作用大于平行行向两侧纵向断根的抑制作用,其中环形断根抑制株高首年和次年分别为20.4%和19.1%,平行行向两侧纵向断根抑制株高首年和次年分别为18.3%和11.4%;环形断根抑制新梢生长长度首年和次年分别为23.7%和25.3%,平行行向两侧纵向断根抑制新梢长度首年和次年分别为18.4%和15.3%。限根栽培第2年,环形断根和平行行向两侧纵向断根处理每株花芽形成数量分别高于对照51.6%和61.7%,每株花束状果枝数分别高于对照84.6%和67.0%。限根栽培改变了树体内赤霉素水平。研究认为,限根栽培明显抑制设施大樱桃的生长,并能显著提高设施大樱桃花芽分化数量;设施大樱桃限根栽培方式可以采用断根修剪处理和箱框式限根处理,断根处理的限根栽培方式以平行行向距主干30cm处两侧纵向断根为宜。     

河南省主要造林树种含碳率比较研究

应用湿烧法对河南省10个主要造林树种不同器官的含碳率进行了测定、分析。结果表明,各组分含碳率为35.5%～47.6%,泡桐枝的含碳率最低,为35.5%,毛白杨根的含碳率最高,为47.6%;将10个树种的含碳率进行聚类分析,含碳率较高的树种是国槐、旱柳、椿树、楝树、法桐,可以作为河南省碳汇造林的优势树种。     

优化设施环境 生产安全农产品

内蒙古敖汉旗从河北保定引进了较先进的节能日光温室和连栋温室,通过采取多层覆盖等措施,实现了在北纬40°左右寒冷地区冬季不加温情况下喜温果菜的安全生产。通过应用外保温空心砖墙、消雾棚膜、内外遮阳、微喷灌、防虫网、诱虫板、燃煤热风炉等配套技术,实行配方施肥,增施沼渣或生物菌肥。推广黄瓜、茄子嫁接和果实套袋栽培,可减少农药污染和有效改善品质。为解决以前设施农业生产中经常出现的诸如:温室采光保温设计不合理、竹木土墙架构的棚室简陋、病虫为害不断加重、连作障碍增加等问题提供了较好的解决方案,并提出了设施农业如何生产出质量安全的农产品的切实可行的途径和方法。     

外置式秸秆反应堆对日光温室内部环境及番茄光合特性的影响

【目的】研究外置式秸秆反应堆在日光温室越冬茬番茄的生产过程中,对日光温室环境因子及番茄光合特性的影响。【方法】以无CO₂发生装置的日光温室为对照温室,以利用外置式秸秆反应堆补充CO₂的日光温室为处理温室,观测在番茄不同生育阶段（苗期、结果期、转色期）温室内CO₂含量、气温、空气相对湿度等环境因子的日变化以及对番茄净光合速率、蒸腾速率、水分利用率和产量的影响。【结果】日光温室内CO₂含量的日变化曲线呈不规则的“N”形,空气湿度昼夜变化曲线呈“V”形。与对照温室相比,在番茄不同生育期,处理温室10:00-11:30 CO₂含量提高了230 μL/L,13:30-16:00提高了84～150 μL/L;夜间平均气温提高了1.5～2.0 ℃,空气相对湿度平均提高了4%～5%;并可显著提高不同生育阶段番茄的净光合速率和水分利用率;极显著降低苗期蒸腾速率,显著提高结果期和转色期番茄的蒸腾速率,产量和经济效益分别提高13 707 kg/hm²和59 310元/hm²。【结论】外置式秸秆反应堆能有效改善越冬茬番茄栽培过程中日光温室内的环境条件,缓解晴天日光温室内CO₂的亏缺,增加番茄的净光合速率和水分利用率,最终提高产量和经济效益。     

除草剂对土壤温室气体排放的影响

试验设对照、尿素、尿素+草甘膦和尿素+丁草胺4个处理,尿素氮用量为200mg·kg-1干土,除草剂用量为10mg有效成分·kg-1干土。在实验室恒温培养条件下,研究除草剂对菜田土壤温室气体排放的影响。结果表明,菜田土壤中施用氮肥显著增加了温室气体N2O、CO2和CH4的排放。尿素氮肥中添加草甘膦显著抑制N2O、CO2的排放,分别比尿素处理降低48.4%和20.2%;添加丁草胺显著抑制N2O排放,比尿素处理降低23.2%,对CO2排放略有减少但不显著;草甘膦和丁草胺对CH4排放都无明显影响。这说明除草剂对土壤温室气体的排放具有显著影响,但不同除草剂品种的效应也存在明显差异。因此,在农田温室气体排放估算时应考虑除草剂的施用对温室气体减排所产生的效果。     

日光温室环境调控配套设备的种类与应用效果

日光温室内的光照、温度、湿度、气体和土壤等环境条件影响温室内植物的生长发育,并与温室经济效益密切相关.根据植物生物学特性,利用卷帘机、节能热风炉、卷膜器、WQT-2型温室气体调质机、DFC-600型温室电除雾防病促生器和WSK-温室温湿度控制器等环境调控配套设备调控温室内的环境因子,以利于温室内植物的正常生长发育,提高日光温室内植物的产量和质量,增加温室的经济效益.     

Yield Maximization in Cassava through a Systematic Approach in Fertilizer Use

Abstract

Maximum yield research (MYR) and maximum economic yield systems (MEY) are important under the present situation of increased demographic changes, which have reduced the per capita availability of both land and food. Among root and tuber crops, cassava is found in a variety of production systems and performs well under various levels of management from low‐input to high‐input systems. A systematic approach in fertilizer use involves the determination and elimination of soil nutrient constraints for balanced supply of all potentially deficient essential nutrients for sustainable high yield. In the systematic approach of determining optimal fertilizer for cassava (Manihot esculenta Crantz) in a Typic Kandiustult soil of Kerala, India, studies on critical levels of nutrients, original nutritional status of the soil, its sorption capacity, and greenhouse/screenhouse nutrient survey were carried out. The critical levels of phosphorus (P) and potassium (K) were determined as 8.23 and 43.5 µg g^?1, respectively. The preliminary analysis of the soil of the experimental site revealed the overall fertility status as very poor. The sorption studies conducted for P, K, copper (Cu), zinc (Zn), manganese (Mn), sulfur (S), and boron (B) indicated P, K, S, and B were limiting in this particular soil. The quantities of these nutrients needed to optimize the soil nutrient status were determined from the preliminary soil analysis, critical levels of nutrients, and sorption curves and found to be 136 µg mL^?1 P, 0.338 meq 100 mL^?1 K, 20 µg mL^?1 S, and 6.025 µg mL^?1 B, respectively. From the greenhouse nutrient survey, N, P, K, and calcium (Ca) were seen as limiting nutrients for this soil; therefore the optimum treatment for cassava was fixed as N‐P‐K at 100:300:300 kg ha^?1, respectively. Field experiments were conducted for two seasons with different levels of the optimum treatment using a short duration (6–7 months) cassava variety, Sree Vijaya. The optimum treatment gave a yield of 43.41 t ha^?1, whereas the yield under the existing practice recommendations was 20–25 t ha^?1. Economic analysis showed this optimum treatment as the best in terms of highest gross return (Rs 1,31,125/‐), net return (Rs 83,150/‐), added return (Rs 70, 178/‐), added profit (Rs 56,142/‐), and benefit cost ratio (BCR) (2.73).     

日光温室番茄栽培不同灌溉方法节水效果的比较

采用日光温室小区栽培番茄的试验方法,对沟灌、膜下滴灌和普通渗灌、节点渗灌4种灌溉方法耗水特点进行研究,探讨了不同方法灌溉灌水量与番茄产量、水分利用效率之间的关系,分析了不同灌溉方法耗水差异产生的机理;得出沟灌、膜下滴灌和普通渗灌、节点渗灌灌水量分别为1473.99、1181.66、1168.078、89.91 m3/hm2,水分利用效率分别为42.00、53.96、54.557、0.37 kg/m3,结果表明,节点渗灌具有灌水量少、水分利用效率高、灌水后对地温影响小等优点,应在日光温室番茄栽培中优先选用。另外,温室内水面蒸发量可以用来指导灌溉,作为判断灌水量的参考。     

Regulated deficit irrigation in green bean and watermelon greenhouse crops

Mediterranean greenhouse growers of watermelon and green bean crops tend to reduce slightly the soil water availability during the flowering phase to enhance the fruit number and yield, but without measuring the soil or the plant water status. This deficit irrigation strategy (RDI) was studied on two representative growth cycles of green bean and one of watermelon. In each case, a well-watered crop acted as control.In the three well-watered vegetable crops, soil water matric potential (SMP) values were between −20 and −30 kPa throughout most of the respective growth cycles. These values avoid water deficits in Mediterranean greenhouse vegetable crops. The watermelon under RDI presented similar SMP to the well-watered crop, except during the flowering period when it reached values of −50 to −60 kPa, which are similar to, or slightly lower than, those recommended to prevent water deficits for cucurbitaceae crops. The autumn–winter and spring cycles of green bean under RDI presented progressively lower SMP values from the vegetative phase to the first fruit setting than the well-watered crops, reaching minimum SMP values of around −55 kPa for the autumn–winter cycle and of −75 kPa for the spring one. These minimum SMP values are similar for the autumn–winter cycle and lower for the spring cycle than those recommended to avoid water deficits in green bean crops grown in medium-fine textured soils. Overall, mild water deficits during flowering of watermelon and green bean crops grown in Mediterranean greenhouses did not improve the final fruit number or yield. In the two spring cycles (watermelon and green bean) the RDI strategy reduced the aboveground biomass and yield, whereas in the autumn–winter green bean cycle the RDI strategy reduced the vegetative biomass but did not affect yield. SMP threshold values can, however, be used by growers as a tool for controlling the equilibrium between the vegetative and reproductive growth of greenhouse soil-grown crops.     

吐鲁番地区温室甜瓜春提早栽培技术

吐鲁番昼夜温差大,光照资源丰富,独特的气候资源为甜瓜的生产提供了有利的条件.现结合吐鲁番当地气候特点,从品种选择、育苗、定植、田间管理、病虫害防治、采收等多个方面,归纳出一套较为完整的甜瓜栽培管理技术,旨为吐鲁番地区甜瓜种植提供技术参考.