生物有机肥部分替代化肥对莴笋生长、产量及品质的影响

为了改善因化肥过量施用导致的蔬菜品质下降、肥料利用率降低和环境污染等问题,通过化肥减量配施生物有机肥,探讨菜田减肥潜力和生物有机肥增效作用。采用随机区组试验,研究不同施肥处理对莴笋产量、品质、光合特性及肥料贡献率的影响。试验共设置6个施肥处理:不施肥(CK1)、100%常规施肥(CK2)、80%常规施肥+200 kg·667m^-2生物有机肥(T1)、80%常规施肥+400 kg·667m^-2生物有机肥(T2)、70%常规施肥+400 kg·667m^-2生物有机肥(T3)、70%常规施肥+200 kg·667m^-2生物有机肥(T4)。结果表明:生物有机肥部分替代化肥可使莴笋的株高、茎长及茎粗不同程度的增加,其中T2效果最优;在相同的生物有机肥施用量下,化肥减施20%较减施30%有助于根系的生长和根系活力的增强;T2处理莴笋叶绿素总量分别比CK1处理和CK2处理提高17.32%和1.74%;T2处理的净光合速率和蒸腾速率最高,分别高于其他处理6.90%～49.35%和6.26%～58.64%;与CK2相...     

不同磷效率玉米自交系干物质积累与分配的影响

采用小区试验,在施磷和不施磷条件下,研究了不同磷效率玉米自交系干物质积累的动态变化.结果表明:在苗期干物质积累过程中呈现出物质由老叶转移至新叶的趋势.其中,磷的中效基因型表现为较强的递减趋势,而低效基因型表现为较弱的递减趋势.在不施磷处理条件下,中效基因型的干物质积累量大于低效基因型.     

水和磷互作对红壤丘岗地区旱作水稻生物量和产量的影响

通过盆栽和大田试验研究了水和磷互作对旱作水稻生物量和产量的影响。研究表明:土壤含水量和施磷量对旱作水稻生物量和产量有极显著的影响,且二者的交互作用十分明显,影响程度以籽粒> 茎>根。上壤含水量为饱和持水量的60%时对旱作水稻生物量和产量影响较大,而80%和100%时几乎没有影响。旱作水稻生物量和产量均随施磷量的增加而增加。这说明控制土壤水分为饱和持水量的80%时就能完全满足旱作水稻的生长,但要求获得较高的产量时必须注意磷肥的投入,或者采取一些凋控措施提高土壤磷的利用率。     

日粮磷和钙磷比例对小型猪(香猪)血清、肠、骨碱性磷酸酶及血清钙磷的影响

36头生长阶段香猪去势公猪 ,通过3×3析因安排分组 ,完全随机区组设计 ,随机分配到9个处理中 ,每个处理4个重复 ,每个重复1头猪。试验两个因子中日粮磷的3个水平分别为0.3 %、0.6 %和0.9 % ;日粮钙磷比例的3个水平为1 :1、1.25 :1和1.5 :1。试验基础日粮由玉米、豆粕、血粉和苜蓿粉组成 ,各处理日粮磷水平和钙磷比例用CaCO3、Na2HPO4 和CaHPO4 调配。从试验开始到结束 ,每隔两周颈静脉采血一次测血清AKP活性和钙、磷 ,并于试验结束时屠宰全部试验猪取小肠和肋骨样测AKP活性。试验结果表明 ,血清AKP活性和第六肋骨AKP活性随日粮磷从0.3 %增加至0.9 %显著下降(P<0.05) ,但十二指肠AKP活性不受日粮磷水平影响。日粮钙磷比例不影响血清、第六肋骨和十二指肠AKP活性(P>0.05)。血清磷随日粮磷增加而增加 ,随日粮钙磷比例增加而下降。血清钙不受日粮磷水平影响 ,但在日粮钙磷比例为1.25 :1时最高     

基于烧失量指数评估滨海沉积物中有机质特征

Understanding organic matter characteristics(e.g., amount and state) of sediments is necessary for evaluating both the sediment and water environments; however, methods that have been proposed to investigate these characteristics are relatively expensive. This study attempted to evaluate the organic matter characteristics of littoral sediments by employing solely the loss on ignition(LOI)method, which is the most economical and accessible method in developing countries. Different types of sediments were first oven dried at 100℃ and then continuously burned at 200, 300, 400, 500, and 600℃ for 4 h at each temperature. The mass LOI at each temperature was calculated and compared with the 100℃ oven-dried weight. Our results suggested that the mass LOI across the temperature range of 200–300℃(LOI_(200-300)):mass LOI at 600℃(LOI_(600)) ratio(LOI_(200-300)/LOI_(600)) could represent different types of sediments as well as the organic matter:organic C ratio. Compared with the sediments unaffected by wastewater, the sediments that were more influenced by the inflow of domestic wastewater had a higher LOI_(200-300)/LOI_(600). Interestingly, LOI_(200-300)/LOI_(600) could also represent changes in the organic matter characteristics as a function of organic matter decomposition in sediments. In conclusion, the organic matter characteristics of littoral sediments could be evaluated using solely the LOI method, particularly with LOI_(200-300)/LOI_(600).     

Integrated agricultural management practice improves soil quality in Northeast China

ABSTRACT

Sustainable agricultural management practices have attracted increasing attention due to their significant roles in benefiting the functions and sustainability of agro-ecosystems. An integrated agricultural practice (IP) in a maize cropping system was developed by changing row spacing, adopting no-tillage and residue return in the Northeast China. A 12-year field study was carried out to evaluate the effect of IP and conventional practice (CP) on soil physical properties, microbial biomass and enzyme activity during the cropping season. The results showed that soil organic matter under IP was increased by 17.4, 9.88 and 6.69% in June, August and October, respectively, than CP. IP enhanced microbial biomass C (by 31.7, 25.1 and 30.4% in June, August and October) and activities of invertase, urease and phosphatase (by 27.2–38.0, 78.9–182 and 9.8–29.0%) compared to CP, possibly attributing to an increase in the soil microbial community. Furthermore, the soil pH, water content, nitrogen and phosphorus contents, microbial biomass and some specific enzyme activities varied with sampling time. It is concluded that IP improved soil quality and health by increasing organic matter content and microbial biomass and activity in maize field in Northeast China, suggesting that IP is a feasible management technology for sustainable agriculture.     

东祁连山不同退化程度高寒草甸土壤有机质含量及其与主要养分的关系

对东祁连山金强河河谷轻度、中度、重度退化高寒草甸土壤有机质含量变化及其与土壤全磷、全氮、速效磷、速效氮含量之间的关系进行了研究。结果表明：随着退化程度的加重,020 cm层土壤有机质、全氮和速效磷含量均不断下降,全磷含量呈现出先降后升但总体呈下降的趋势,但速效氮含量则不断上升,各养分的变化差异均达到极显著水平(P<0.01)。在划分的轻度退化草地土壤中,有机质含量分别与全磷、全氮、速效磷、速效氮含量之间均不存在显著的相关关系(P>0.05),另外所划分的中度退化和重度退化草地也同样如此。但是通过把3个不同程度退化草地结合起来作为整体进行综合分析,结果表明,除了全磷,土壤有机质含量分别与全氮、速效氮、速效磷含量三者之间存在极显著的相关关系(P<0.01)。在较大尺度上,有机质可以作为土壤营养状况的主要判断指标。在研究高寒草地土壤养分状况及其综合评价中,要特别注意其时空异质性,要重视尺度问题。     

日粮维生素D和钙水平对冬毛期水貂生长性能、营养物质消化率及氮、钙、磷代谢的影响

本试验旨在研究当日粮钙磷比一定时,维生素D和钙水平对冬毛期水貂生长性能、营养物质消化率及氮、钙、磷代谢的影响。随机选取（135±5）日龄、健康雄性水貂117只,分成9组,每组13个重复,每个重复1只。采用3×3双因素随机试验设计,设3个维生素D水平,分别为2 300、4 300、6 300 IU/kg;设3个钙水平,分别为2.0%、2.4%、2.8%,钙磷比固定为1.7∶1,配制9组试验日粮,分别为：Ⅰ组（2 300 IU/kg维生素D＋2.0%钙）、Ⅱ组（4 300 IU/kg维生素D＋2.0%钙）、Ⅲ组（6 300 IU/kg维生素D＋2.0%钙）、Ⅳ组（2 300 IU/kg维生素D＋2.4%钙）、Ⅴ组（4 300 IU/kg维生素D＋2.4%钙）、Ⅵ组（6 300 IU/kg维生素D＋2.4%钙）、Ⅶ组（2 300 IU/kg维生素D＋2.8%钙）、Ⅷ组（4 300 IU/kg维生素D＋2.8%钙）、Ⅸ组（6 300 IU/kg维生素D＋2.8%钙）。预试期13 d,正试期60 d。结果表明：①各组水貂料重比差异极显著（P<0.01）,Ⅱ组最低。钙水平对料重比有显著影响（P<0.05）,维生素D水平对料重比有极显著影响（P<0.01）。②钙水平可极显著影响粗脂肪消化率（P<0.01）,其中2.8%水平极显著低于2.0%和2.4%水平（P<0.01）。③日粮维生素D和钙水平对水貂氮代谢指标均无显著影响（P>0.05）。④各组水貂粪钙、粪磷、钙消化率、磷消化率均差异极显著（P<0.01）,其中Ⅱ组钙消化率、磷消化率最高,Ⅲ组次之。钙水平可极显著影响粪钙、粪磷、钙消化率、磷消化率（P<0.01）,2.0%水平可极显著降低粪钙、粪磷含量（P<0.01）,极显著提高钙消化率及磷消化率（P<0.01）。维生素D水平对钙消化率影响显著（P<0.05）,对粪磷、磷消化率影响极显著（P<0.01）,2 300~4 300 IU/kg维生素D水平有利于提高钙消化率、磷消化率,降低粪磷含量。综合考虑各项指标,在本试验条件下,日粮中钙磷比为1.7∶1,维生素D水平为2 300~4 300 IU/kg、钙水平为2.0%时,冬毛期水貂料重比及钙、磷排放量较低,而粗脂肪、钙、磷消化率较高。     

Lactobacillus amylophilus JCM1125在生长限制条件下的代谢特性

在以小麦淀粉、玉米淀粉、马铃薯淀粉和可溶性淀粉为碳源代替葡萄糖为碳源的 MRS培养基上检测了菌株 L actobacillus amylophilus JCM112 5活菌数的增殖状况以及葡萄糖和有机酸的代谢特征同时测定了 p H值的变化。结果表明以淀粉为碳源时菌株先分解淀粉成葡萄糖并累积到一定数量后再加以利用 ;活菌数呈现双曲线增长现象 ;丙酮酸、乳酸、乙酸和柠檬酸及另一未知有机酸的数量发生了较大的变化。