收获期和酶制剂对青贮玉米秸秆品质影响的研究

以蜡熟期和完熟期玉米秸秆为原料,分别添加夏盛酶制剂0、1、2、4 kg/t进行青贮,青贮结束后对其发酵品质和营养价值进行了评定。结果表明,添加夏盛酶后蜡熟期青贮玉米秸秆的感官品质得到改善,显著降低了玉米秸秆的酸性洗涤纤维和中性洗涤纤维的含量（P〈0.01）;添加夏盛酶后完熟期青贮玉米秸秆的感官品质也得到改善,也显著降低了完熟期玉米秸秆的酸性洗涤纤维和中性洗涤纤维的含量（P〈0.01）,还提高了CP的含量（P〈0.01）,但效果仍差于蜡熟期的没加酶组,说明收获期是比青贮酶更能影响青贮玉米秸秆青贮质量的因素,玉米秸秆青贮的最好时期是蜡熟期。     

土壤氮素矿化与土壤供氮能力——Ⅱ.矿化氮量与作物吸氮量的关系

根据土壤氮素矿化势和氮素矿化累积计算了不同时期土壤氮素矿化量。结果表明,两种方法计算出来的矿化氮量均与作物吸氮量有良好相关,而前者效果更优。作物吸收的氮素大约等于土壤矿化氮的2/5,等于土壤中起始NO_3~--N和作物生长期间矿化氮之和的2/3。这一结果为定量预测作物不同生长时期土壤供氮和确定氮肥适宜用量、施用时期提供了有用依据。     

铜绿丽金龟发育起点温度与有效积温的研究

在实验室设置的5个不同恒温条件下,对铜绿丽金龟各虫态的发育历期,发育起点温度和有效积温进行了研究.结果表明:随着温度的升高,发育历期逐渐缩短;铜绿丽金龟0卵、1龄幼虫、2龄幼虫,3龄幼虫,整个幼虫期、蛹、成虫以及全世代的发育起点温度C分别为:11.93299±0.608208、10.09588±0.636162、10.11822±0.626651、4.10728±0.5631、4.503128±0.517028、10.42225±0.22592、9.180074±0.73464和6.959769±0.535106℃.相应的有效积温K分别为:128.4972±5.18851、353.4484±14.77367、374.0462±15.49812、3 139.8566±91.3068、4 132.557±112.839、168.6237±2.34459、526.20794±24.66807和4 587.01326±146.82423℃.根据发育起点温度和有效积温,预测出铜绿丽金龟在丹东地区的年发生代数为1年1代,结果与实际情况符合.     

Effect of temperature and rhizosphere processes on pedogenic carbonate recrystallization: Relevance for paleoenvironmental applications

In soils of arid and semiarid climates, dissolution of primary (lithogenic) carbonate and recrystallization with CO₂ from soil air leads to precipitation of pedogenic carbonates and formation of calcic horizons. Thus, their carbon isotope composition represents the conditions prevailing during their formation. However, the widespread use of the isotopic signature (δ¹³C, δ¹⁸O, Δ¹⁴C) of pedogenic carbonates for reconstruction of local paleovegetation, paleoprecipitation and other environmental conditions lacks knowledge of the time frame of pedogenic carbonate formation, which depends on climatic factors. We hypothesized that temperature-dependent biotic processes like plant growth and root and rhizomicrobial respiration have stronger influence on soil CaCO₃ recrystallization than abiotic temperature-dependent solubility of CO₂ and CaCO₃.To assess the effect of temperature on initial CaCO₃ recrystallization rates, loess with primary CaCO₃ was exposed to ¹⁴CO₂ from root and rhizomicrobial respiration of plants labeled in ¹⁴CO₂ atmosphere at 10, 20 or 30 °C. ¹⁴C recovered in recrystallized CaCO₃ was quantified to calculate amounts of secondary CaCO₃ and corresponding recrystallization rates, which were in the range of 10⁻⁶-10⁻⁴ day⁻¹, meaning that 10⁻⁴-10⁻²% of total loess CaCO₃ were recrystallized per day. Increasing rates with increasing temperature showed the major role of biological activities like enhanced water uptake by roots and respiration. The abiotic effect of lower solubility of CO₂ in water by increasing temperature was completely overcompensated by biotic processes. Based on initial recrystallization rates, periods necessary for complete recrystallization were estimated for different temperatures, presuming that CaCO₃ recrystallization in soil takes place mainly during the growing season. Taking into account the shortening effect of increasing temperature on the length of growing season, the contrast between low and high temperature was diminished, yielding recrystallization periods of 5740 years, 4330 years and 1060 years at 10, 20 and 30 °C, respectively. In summary, increasing CaCO₃ recrystallization rates with increasing temperature demonstrated the important role of vegetation for pedogenic CaCO₃ formation and the predominantly biotic effects of growing season temperature.Considering the long periods of pedogenic carbonate formation lasting to some millennia, we conclude that methodological resolution of paleoenvironmental studies based on isotope composition of pedogenic carbonates is limited not by instrumental precision but by the time frame of pedogenic carbonate formation and hence cannot be better than thousands of years.     

两优培九栽培试验研究

通过引种观察和栽培试验 ,研究了解两优培九在信阳特殊生态类型区的生物学特性和产量表现 ,据此提出相应的栽培应用技术     

高丹草新品种在河北平原农区的引进筛选

在河北平原农区,通过对国内外11个高丹草新品种的产草量、粗蛋白产量、物候期、分蘖力、再生性、株高等性状的研究分析,结果表明:以青饲、青贮饲喂牛为目的,表现最好的品种为健宝,不仅产草量高、粗蛋白产量、分蘖能力、再生性、长势均较好。其次为晋草1号、瑞奥3号。高丹草在河北平原农区春播、夏播均可,春播可刈割三次,夏播可刈割二次。     

不同时期施基肥对葡萄生长及产量的影响

对葡萄春、秋不同时期施用基肥的效果进行了田间对比试验,结果表明,秋季与春季施基肥对葡萄植株的营养生长没有表现出差异,但在产量和浆果含糖量方面,秋施基肥略优于春施基肥。春施基肥可以节省劳动力,降低生产投入成本,在秋施基肥不便的情况下,可以考虑改为春季施肥。     

Effects of seed treatments on the germination of Atriplex nummularia Lindl.

Laboratory experiments were conducted to determine the influence of length of soaking period and water temperature treatments on the germination of Atriplex nummularia. Germination percentages increased significantly (P≤0,01) with increasing soaking period in water with a temperature of 20°C, while there was a tendency for a decrease in germination at the higher water temperature (30°C) treatment. The fruits were almost fully imbibed after 8 days of soaking at both water temperature treatments. Fruits germinated better in pots than in petri dishes, but for naked seeds the opposite was the case. Some of the unexplained findings should be further investigated.     

甘蓝型油菜生育期天数与产量构成性状的相关分析

对四川省大面积推广的甘蓝型油菜品种各生育期天数与单株产量及产量构成性状进行相关性和通径分析,结果表明:(1)营养生长天数和角果成熟天数均与单株产量显著正相关,开花天数与单株产量显著负相关;营养生长天数与每果粒数极显著正相关,但与千粒重负相关;开花天数与产量构成性状负相关;角果成熟天数与每果粒数及千粒重极显著正相关,但与单株有效角果数负相关.(2)各生育期天数对单株产量的作用主要通过产量构成性状的间接作用形成;生育期性状对每果粒数的作用大小为角果成熟天数＞营养生长天数＞开花天数;对千粒重的作用效果为角果成熟天数＞开花天数＞营养生长天数.因此,在甘蓝型油菜品种的选育中,在进行产量构成性状选择的同时,辅以生育期天数的选择,充分利用各性状间的相互作用,提高单株产量以到达高产的目的.     

广西桂平市荔枝木毒蛾的防治研究

【目的】研究掌握木毒蛾在广西荔枝上的发生危害规律,筛选出高效的防治药剂,为木毒蛾的田间防治提供科学依据。【方法】1)通过室内继代饲养观察及田间调查相结合,掌握木毒蛾的生育历期；2)采用喷雾法对木毒蛾进行室内毒力测定及田间防治试验【结果】1)木毒蛾在广西的发生代数为一年一代,幼虫期7龄,幼虫期50-60天,以幼虫在卵壳内越冬。2)试验结果表明,施药24h后, 20%甲氰菊酯EC、2.5%敌杀死EC、４.5%高效氯氟氰菊酯EC对木毒蛾的防效＞90%,100克/升联苯菊酯EC、10%除尽SC的防效＞80%,40%辛硫磷EC、480克/升毒死蜱EC60克/升乙基多杀霉素SC＜80%。【结论】20%甲氰菊酯EC、2.5%敌杀死EC、4.5%高效氯氟氰菊酯EC可做为荔枝木毒蛾暴发时防治的首选药剂,