Time filter

Source Type

Zuo B.,Nanjing Agricultural University | Qian H.,Inner Mongolia Academy of Agriculture and Animal Husbandry | Wang Z.,Nanjing Agricultural University | Wang X.,Xinjiang Bazhou Livestock Station | And 7 more authors.
Asian-Australasian Journal of Animal Sciences | Year: 2013

The average twin lambing rate of Bayanbulak sheep is 2% to 3%. However, a flock of sheep with a close genetic relationship and an average of 2 to 3 lambs per birth has been found recently. To determine the major genes controlling the prolificacy of the flock in the present study, the flock was designated A while 100 normal Bayanbulak sheep were randomly selected to comprise the control flock B. Ligase detection reaction method was applied to detect and analyze the 10 mutational loci of the 3 candidate prolificacy genes including bone morphogenetic protein type I receptors, bone morphogenetic protein 15, and growth differentiation factor 9. The 10 mutational loci are as follows: FecB locus of the BMPR-IB gene; FecXI, FecXB, FecXL, FecXH, FecXG, and FecXR of the BMP15 gene; and G1, G8, and FecTT of the GDF9 gene. Two mutations including BMPR-IB/FecB and GDF9/G1 were found in Bayanbulak sheep. Independence test results of the two flocks demonstrate that the FecB locus has a significant effect on the lambing number of Bayanbulak sheep. However, the mutation frequency of the G1 locus in GDF9 is very low. Independence test results demonstrate that the GDF9 locus does not have a significant impact on the lambing performance of Bayanbulak sheep. Among the 10 detected loci, BMPR-IB/FecB is the major gene that influences the high lambing rate of Bayanbulak sheep. Copyright © 2013 by Asian-Australasian Journal of Animal Sciences. Source

Li H.,China Agricultural University | Wang Q.J.,China Agricultural University | He J.,China Agricultural University | Li H.W.,China Agricultural University | And 5 more authors.
Agronomy Journal | Year: 2014

As a typical semi-humid area with a wheat (Triticum aestivum L.)-maize (Zea mays L.) annual double-cropping system, Beijing has the lowest food production per capita and is suffering from severe soil degradation and low seedbed temperature in winter. This study evaluated the permanent raised bed (PRB) system in Beijing from 2005 to 2011 to investigate the effects of combining no tillage, residue cover, and controlled traffic with raised beds for improving soil properties. We found that the overall soil bulk density (0-30 cm) in PRB plots was significantly (P < 0.05) lower (by 12.4%) than that in traditional tillage (TT) plots, while the penetration resistance in the 10- to 20- and 20- to 30-cm soil layers of PRB plots was 18.2 and 26.1% lower (P < 0.05), respectively, than that of TT. The percentage of water-stable soil macroaggregates (>0.25 mm) in the PRB plots was 89.8% (P < 0.05) higher than in the TT plots, while the soil temperature was approximately 1.3 and 1.0°C higher under TT at the 5- and 15-cm depths, respectively, in winter. With these improvements, yields of PRBs appeared to have an increasing trend compared with no-till and TT treatments. © 2014 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved. Source

Li H.,China Agricultural University | Wang Q.,China Agricultural University | He J.,China Agricultural University | Jing P.,China Agricultural University | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2012

As a key part of the knotter, knotter driving pulley is the total power source of the knotter used on briquetters. The parameters of knotter driving pulley are main factors for affecting the knotting rate. Two kinds of CTRC knotters (CTRC_I and CTRC_II) were designed to solve the present knotting problems, which including mis-clipping, mis-cutting and mis-tripping off the twine. CTRC_I was composed of CTRC basal part and reversed "9" type cam block, while CTRC_II was composed of CTRC basal part and arc-tangent type cam block. The comparison was carried out among CTRC_I, CTRC_II and New Holland knotter driving pulleys indoor. The results showed that the stable knotting rate of CTRC_I pulley (90.0%) was significant higher than that of New Holland (83.5%) and CTRC_II (65.0%) types of pulleys. The best stable knotting rate was obtained under three combinations: New Holland with sisal twine, CTRC_I with polypropylene twine and CTRC_I with sisal twine and was 22.7%~53.5% higher than the other three combinations. During the experiments, mean maximum pull tension was got by the CTRC_II type pulley, while the minimum pull tension was got by the CTRC_I type pulley. At last, the knot quality was the highest for CTRC_I pulley while the twine dosage was also largest for it in comparison with the CTRC_II and New Holland pulleys. Meanwhile, the twine dosage was the largest at 70 r/min (99.5 mm) and smallest at 40 r/min (94.8 mm). Finally, the knotting performance of CTRC_I and New Holland pulleys were proved to be better than CTRC_II pulley by comprehensive benefit analysis through combining the methods of analytic hierarchy process and effect coefficient. Combination of the CTRC_I pulley and polypropylene rope was the best operating mode among the six different combinations. Source

Zhang Z.,China Agricultural University | Qiang H.,China Agricultural University | McHugh A.D.,International Maize and Wheat Improvement Center | He J.,China Agricultural University | And 3 more authors.
Soil and Tillage Research | Year: 2016

An arid environment under long-term traditional agriculture has resulted in serious environmental and agricultural problems on a number of fragile soils with distinguishing physical and chemical properties in Northern China. Conservation agriculture is an alternative sustainable agriculture management system, which contributes to conserving soil, water and fertility, while changing vertical distribution of soil organic matter (SOM). No-tillage with straw cover (NTSC) and traditional tillage with straw removal (TTSR) in four regions of northern China (Tailai, Wuchuan, Nailin, Yaodu) were investigated to determine how tillage and soil type affected SOM stratification. SOM content, total N (TN), soil water content (SWC) and soil bulk density (pd) in the 0-5, 5-15, 15-30 and 30-40cm layers and the time since implementation of tillage treatments were evaluated. The top layer (0-5cm) and total SOM content were markedly improved by NTSC. The influence dramatically decreased with depth in all sites. SOM content increased during the first 10 years following NTSC implementation, but the rate of increase was reduced in subsequent years. There was high positive correlation between SOM and SWC, high positive correlation between SOM and TN, and high negative correlation between SOM and bulk density. Effects of conservation measures on SOM content were expressed by a stratification ratio. The stratification ratio of SOM, in most sites, under long-term NTSC were >2. These results from northern China, suggest that long-term no-tillage with straw cover significantly improved topsoil conditions and whole of soil profile SOM and this improvement was obvious in different layers. © 2015 Elsevier B.V. Source

He J.,China Agricultural University | Wang Q.,China Agricultural University | Li H.,China Agricultural University | Lu C.,China Agricultural University | And 2 more authors.
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2013

The effect of no-till (NT) opening seedbed characteristics on soil moisture, crop growth, yield and water use efficiency (WUE) was studied in the field experiment at Daxing in Beijing in 2008-2010. The results indicated that no-till opening seedbeds could increase the capacity of water storage. Compared with traditional tillage seedbed, volumetric soil water content increased by 0.2%-2.7% in 0-30 cm soil layer and the crops growth were also promoted. The best results were achieved by the seedbed of NT with the opening depth of 20 cm. Compared with traditional tillage seedbed, NT with the opening depth of 20 cm increased winter wheat yield and WUE by 2.4% and 7.4%, and summer maize yield and WUE by 1.2% and 1.5%, respectively. The study showed that 20 cm could be the suitable opening depth for no-till seeding in northern China plain. Source

Discover hidden collaborations