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91.
砂土地肥料配施对小麦产量和土壤肥力的影响 总被引:1,自引:0,他引:1
彩四因子干净人通用旋转设计,研究了砂土地施用有机肥、氮、肥、磷肥和钾肥对小麦产量的作用和对土壤肥力的影响及其施肥因子之间的交互作用和最适配比。结果表明:有机肥、氮肥、磷肥和钾肥与小麦产量呈二次回归关系,砂土地要提高产量和培肥地力应立足于肥料配合施用,重施有机肥,酌情多施磷肥。 相似文献
92.
为了解甘蔗产区土壤养分状况,并根据养分丰缺情况进行合理科学的施肥,最终实现甘蔗高产高糖,对云南省临沧市沧源蔗区采集的185份土壤样品进行养分测定,结果表明:沧源蔗区土壤大部分呈微酸性,53.51%土壤样品的pH在5.5~6.5;有机质含量平均为2.74%;全氮含量极低,75.14%的土壤样品小于0.050%,平均为0.042%;碱解氮含量中等,平均为101.43 mg/kg;全磷含量低,平均为0.082%;有效磷含量低,平均为6.33 mg/kg;全钾含量低,52.97%的土壤样品含量在1.01%~1.50%,平均为1.403%;速效钾含量中等,平均为146.32 mg/kg;微量元素有效锌缺乏,79.75%的含量低于1.5 mg/kg;有效锰、有效铁和有效铜93%以上的土壤样品都高于临界值,铜、铁和锰不缺乏。根据土壤养分分析结果,在沧源蔗区建议有机肥结合速效氮磷钾复合肥施用,有利于甘蔗的高产高糖。 相似文献
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95.
外来杂草刺萼龙葵及其风险评估 总被引:13,自引:0,他引:13
外来入侵生物已对世界各国的自然生态系统、农业生产及公众健康造成了严重危害。刺萼龙葵(Solanum rostratum)起源于北美洲,其繁殖和适应能力很强,是具有潜在危险的外来有害杂草。对刺萼龙葵的分布、生物生态学特性、经济和生态影响及其控制和管理措施等进行了系统综述。根据生物生态学特性、潜在危险及管理控制的难度等特点,对刺萼龙葵进行了风险评估,得出其风险值为86,属高度危险的检疫性有害生物。应当高度重视刺萼龙葵的入侵,积极采取措施控制其危害蔓延。 相似文献
96.
Zhi-Shan Lin Zhi-Fu Cui Xiang-Yan Zeng You-Zhi Ma Zeng-Yan Zhang Toshiki Nakamura Goro Ishikawa Kazuhiro Nakamura Hisashi Yoshida Zhi-Yong Xin 《Euphytica》2007,158(1-2):109-118
Chromosome compositions of seven lines, derived from hybrids between a wheat cultivar and the wheat-Thinopyrum intermedium addition line Z6, with barley yellow dwarf virus (BYDV) resistance, were determined by genomic in situ hybridization, cytogenetic and SSR assays. The results showed that
line N522 was a disomic addition line, lines N420 and N439 were 2Ai-2(2B) chromosome substitution lines, lines N431 and N452
were 2Ai-2(2D) chromosome substitution lines, line N523 was a 2Ai-2S(2D) ditelosomic substitution line, and line N530 was
a double ditelosomic line with the mitotic chromosome number of 2n = 40 + 4t. One pair of telosomes in line N530 lacked several proximal SSR markers of chromosome 2AS, but possessed certain
terminal markers, which were consistent with an acrocentric structure, and the other pair of chromosome arms were presumably
2Ai-2S telosomes with BYDV-resistance. These wheat-Th. intermedium lines provide useful genetic resources for developing alien chromosome translocation lines. 相似文献
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99.
Youzun Xu Lixiao Nie Roland J. Buresh Jianliang Huang Kehui Cui Bo Xu Weihua Gong Shaobing Peng 《Field Crops Research》2010,115(1):79-84
In double rice-cropping system in China, zero tillage in late-season rice with straw return from early season rice is an emerging technology for saving inputs, shortening the lag time between rice crops, avoiding straw burning, and conserving natural resources. The objective of this 2-year field study was to determine the effects of tillage and straw return on N uptake, grain yield, and N use efficiency of late-season rice. Treatments were arranged in a split-plot design with four combinations of tillage and straw return as main plots and three N management practices as subplots. Tillage was either conventional soil puddling or zero tillage with newly harvested crop residue from early season rice either removed or placed on the soil surface without incorporation. The N treatments were zero-N control, site-specific N management (SSNM), and farmers’ N-fertilizer practice (FFP). Straw return regardless of tillage or N management did not reduce rice yield. In the second year, straw return significantly increased grain yield in the zero-N control. Chlorophyll meter readings at heading and total N uptake at maturity were higher with straw return in the zero-N control, suggesting that straw provides nutrients to rice in the late growing period. Zero tillage did not reduce N uptake, grain yield, and N use efficiency compared with conventional tillage. Despite large differences in timing and rate of N application between FFP and SSNM, these two N treatments resulted in comparable N uptake and grain yield of late-season rice regardless of tillage and straw return. These results suggest that zero tillage after early rice with straw return could replace conventional tillage for late rice in the double rice-cropping system in China. 相似文献
100.
Increasing water scarcity has necessitated the development of irrigated rice systems that require less water than the traditional
flooded rice. The cultivation of aerobic rice is an effort to save water in response to growing worldwide water scarcity with
the pressure to reduce water use and increase water productivity. An accurate estimation of different water balance components
at the aerobic rice fields is essential to achieve effective use of limited water supplies. Some field water balance components,
such as percolation, capillary rise and evapotranspiration, can not be easily measured; therefore a soil water balance model
is required to develop and to test water management strategies. This paper presents results of a study to quantify time varying
water balance under a critical soil water tension based irrigation criteria for the cultivation of non-ponded “aerobic rice”
fields along the lower parts of the Yellow River. Based on the analysis and integration of existing field information on the
hydrologic processes in an aerobic rice field, this paper outlines the general components of the water balance using a conceptual
model approach. The time varying water balance is then analyzed using the feedback relations among the hydrologic processes
in a commercial dynamic modeling environment, Vensim. The model simulates various water balance components such as actual
evapotranspiration, deep percolation, surface runoff, and capillary rise in the aerobic rice field on a daily basis. The model
parameters are validated with the observed experimental field data from the Huibei Irrigation Experiment Station, Kaifeng,
China. The validated model is used to analyze irrigation application soil water tension trigger under wet, dry and average
climate conditions using daily time steps. The scenario analysis show that to conserve scarce water resources during the average
climate years the irrigation scheduling criteria can be set as −30 kPa average root zone soil water tension; whereas it can
be set at −70 kPa during the dry years, however, the associated yields may reduce. Compared with the flooded lowland rice
and other upland crops, with these two alternatives irrigation event triggers, aerobic rice cultivation can lead to significant
water savings. 相似文献