砂姜黑土区不同肥料配方一次性施肥对玉米产量和经济效益的影响

对砂姜黑土区玉米进行田间试验,目的在于筛选出适合当地的复合肥配方,减少肥料用量,增加经济效益。结果表明:5个处理中以缓释肥(25-10-10)处理产量最高,达7 954 kg/hm2,其利润也最高。     

从有机碳营养的视角透视农作物现象

透过施与不施有机碳肥的农作物生长中的几类现象,分析有机碳营养对土壤生态和植物营养的影响.试验表明,有机碳肥可促进土壤微生物繁殖,促进作物叶片的光合作用,促进作物对矿物营养的平衡吸收,使矿物质营养能以有机配位零电价进入植株,对提高作物产量和品质有不可替代的作用.提出测土配方施肥应把修补“碳短板”作为配方的内容.     

Partial Sperm beta1 Integrin Subunit Deletion Proves Its Involvement in Mouse Gamete Adhesion/Fusion

We have previously shown, using antibodies, that the sperm alpha6beta1 integrin is involved in mouse gamete fusion in vitro. Here we report the conditional knockdown of the sperm Itgb1 gene. It induced a drastic failure of sperm fusogenic ability with sperm accumulation in the perivitelline space of in vitro inseminated oocytes deleted or not for the Itgb1 gene. These data demonstrate that sperm, but not oocyte, beta1 integrin subunit is involved in gamete adhesion/fusion. Curiously, knockdown males were fertile in vivo probably because of the incomplete Cre-mediated deletion of the sperm Itgb1 floxed gene. Indeed, this was shown by Western blot analysis and confirmed by both the viability and litter size of pups obtained by mating partially sperm Itgb1 deleted males with females producing completely deleted Itgb1 oocytes. Because of the total peri-implantation lethality of Itgb1 deletion in mice, we assume that sperm that escaped the Itgb1 excision seemed to be preferentially used to fertilize in vivo. Here, we showed for the first time that the deletion, even partial, of the sperm Itgb1 gene makes the sperm unable to normally fertilize oocytes. However, to elucidate the question of the essentiality of its role during fertilization, further investigations using a mouse expressing a recombinase more effective in male germ cells are necessary.     

大白菜“3414”施肥试验初报

通过大白菜测土配方施肥"3414"试验,结果表明,以氮肥增产效果最佳,钾肥次之,氮磷钾施肥效应为N>K>P。通过三元二次肥料效应模型回归方程算出大白菜667 m2最高产量3 532.82 kg,667 m2N、P2O5、K2O最佳施用量分别为21、3、12 kg,m(N)∶m(P2O5)∶m(K2O)=1∶0.14∶0.57。     

配方肥在小麦上的应用

通过田间试验探讨了施用不同配比的配方肥对小麦产量、经济效益的影响。结果表明,18-20-7缓控释肥配方肥增产效果明显,经济效益显著,每667 m~2产量及经济效益较普通复合肥处理分别提高12.2%和102.2元。可为配方肥在小麦上合理施用提供依据和技术指导。     

控释尿素在冬小麦上的一次性施肥研究

在驻马店市地力为中、低水平的砂姜黑土上进行冬小麦田间试验,研究控施尿素在小麦上一次性施肥技术。结果表明:两个试验点产量最高的为控释尿素A(一次性基施处理),达到7 500.4 kg/hm~2和8 145.1 kg/hm~2,与等氮量处理相比提高了180.1 kg/hm~2和224.9 kg/hm~2;在最佳施氮量的基础上减施20%的氮肥,与农民习惯施肥相比产量差异不显著,总体表现为不降低冬小麦产量,降低了施肥次数和劳动强度。     

施肥对土壤理化性状及玉米产量的影响

通过10年研究化肥与根茬、秸秆和有机肥定量配比施肥对土壤肥力、养分平衡及玉米产量的影响,结果表明:玉米单施化肥产量下降了7.9%;化肥 根茬产量持平;化肥 根茬 秸秆,土壤肥力和玉米产量同步上升,玉米增产17.1%;化肥 根茬 有机肥效果更佳,土壤肥力指标均上升,玉米增产32.1%。这对制定科学合理的培肥地力施肥措施,建立高产、优质、低耗的培肥制度,具有十分重要的意义。     

几种确定作物施肥量的方法

确定作物施肥量是配方施肥技术中的核心问题。确定施肥量主要考虑作物产量、土壤供肥量和肥料利用率。介绍土壤养分分级法,目标产量配方法,田间试验法,氮、磷、钾比例法和经验施肥法确定施肥量的技术方法。     

Nitrous oxide emissions from an Uruguayan argiudoll under different tillage and rotation treatments

Lack of local data limits estimation of nitrous oxide (N₂O) emissions from different land uses of Uruguay. As a first step towards obtaining local information, we measured from August 2003 to September 2004 N₂O fluxes from a rotation-by-tillage experiment established in 1993 and from a nearby natural pasture (NP). Nitrous oxide emission rates were measured on an event-driven basis by using the closed chamber technique with six replicates per treatment. Fluxes varied considerably with time and the higher rates (more than 30 g N ha⁻¹ day⁻¹) were generally associated with periods of high soil water content, high temperature, and/or decreasing soil nitrate. We could not identify, however, any statistically significant correlation between flux and these variables. Throughout the evaluation period, fluxes from crops or cultivated pastures tended to be higher than those from NP, but the effects of tillage (no-till and conventional tillage) or rotation (continuous tillage and rotation with pasture) were not consistent. The application of 112 kg N ha⁻¹ to barley did not increase N₂O fluxes probably due to a high fertilizer use efficiency caused by the recommended three-split application and by the lack of rain during this period. The annual cumulative flows of different treatments compared well with those estimated using IPCC methodology, but the high spatial and temporal variability observed in this one-year study indicate that further research is needed to obtain reliable data on N₂O fluxes from agricultural soils of Uruguay.     

不同氮磷钾施肥水平对超级稻产量的影响

探讨各种土壤肥力状况下,不同氮磷钾施肥水平对超级稻(准两优1202)产量的影响,提出了超级稻合理的氮磷钾施肥水平和配比。