- Ewetola Esther Abosede;
Soil erosion induced by inappropriate tillage remains a serious problem on many agricultural fields in the humid tropics. Studies were conducted between 2004 and 2006, on an Alfisol in Ogbomoso in the Southern Guinea Savanna of Nigeria to evaluate the effectiveness of Vetiver Grass(Vetiveria nigritana) Strips(VGS) under different tillage systems. The experiment was split-plot laid out in a randomized complete block design with two replications on 6% slope with 18 runoff plots. Main plot treatments were tillage systems; Manual Clearing(MC), Ploughing(P) and Ploughing plus Harrowing(PH). Subplot treatments were VGS spaced at intervals of 5 m(eight strips) and 10 m(four strips) with the control(no-vetiver). Runoffs and soil losses were collected after each major storm. Chemical analyses of eroded sediments and runoff were determined. Data were analyzed using ANOVA at p<0.05. The results showed that tillage had no significant reduction in runoffs and soil losses, but they were reduced with MC compared with P and PH. Mean total runoff on 5 and 10 m VGS plots were significantly(p<0.05) lower than that of the control by 74.4% and 45.0%, respectively. Corresponding soils loss on 5 and 10 m VGS plots were 27.1% and 53.5%, respectively. Mean NO3-N levels in runoff water were lower under PH plots than those under MC plots by 79.0% and 66.5%, respectively in 2004 and 2006 growing seasons. VGS spaced at 5 m significantly(p<0.05) reduced NO3-N loss than the control by 108.8% in 2004. Nutrients loads of eroded sediments were consistently higher for the control(no-vetiver) plots and least for 5 m VGS plot. Carbon, nitrogen and phosphorus contents of eroded sediments were 90%-92.4%, 83%-83.6% and 97%-97.8%, respectively, and were lower on 5 m than other treatments. Maize grain yield was significantly(p<0.05) affected by both tillage and VGS spacing only in 2005 growing season. P plot produced higher grain yield than MC and PH by 79.9% and 99.1%, respectively. Also, grain yield on VGS plot was significantly(p<0.05) higher on 5 and 10 m VGS plots than the control by 82.2% and 85.4%, respectively. The significant beneficial effect of PH in producing higher yields was dwarfed by the potential danger of soil erosion in the absence of a soil erosion control measure. The results showed that a balance needed to be struck between mechanical clearance and protective measure against soil erosion.
2017年04期 v.24;No.69 1-18页 [查看摘要][在线阅读][下载 547K] [下载次数：35 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：25 ] - Ge Yu;Wang Yun-li;Xu Wen-long;Cui Chong-shi;Qu Shu-ping;
In the literature there are many reports on the composition and properties of pumpkin seed oil; however, few is known about the effect of different stages of seed development on various fatty acid profiles in developing seeds. The objective of this study was to provide the changes of various fatty acid accumulations in seed oil obtained from the seeds of three pumpkin varieties belonging to the species Cucurbita maxima and Cucurbita pepo. Unsaturated acids(oleic and linoleic) were dominant in various fatty acids, which constituted 38.9%-49.1% and 29.4%-42.7% of the total fatty acids at seed maturity for three pumpkin varieties, respectively, while other fatty acid concentrations except for palmitic acid all did not reach 10%. Different varieties exhibited greater effect on various fatty acid contents and the total fatty acid contents in the seeds of pumpkin rather than the species. On the whole, palmitic acid profiles of the seed oil in three varieties all followed the fluctuant decrease during all the stages of seed development, but palmitoleic acid and the total fatty acid profiles of the seed oil in three varieties were just the opposite. Stearic, oleic and linoleic acid profiles of the seed oil in three varieties all experienced the third pattern that fluctuated during all the stages of seed development, but no significant differences in these three fatty acid concentrations were found from the beginning to the end. Linolenic acid concentrations of three varieties were on the decline and ultimately close to zero. Myristic and arachidic acid profiles of the seed oil followed different trends in three varieties. Among them, myristic and arachidic acid profiles of the seed oil of Yinhui-1 fluctuated downward all the time until seed maturity, but those of 0238-1 and Jinhui-2 completely changed oppositely.
2017年04期 v.24;No.69 19-24页 [查看摘要][在线阅读][下载 349K] [下载次数：36 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：24 ] - Zhou Wei-quan;Cheng Gong;Mansuer·Nasier;Yang Wen-li;Zhao Shi-rong;Qi Yan-qiao;Zhang Shi-kui;Liao Kang;
To study the effects of different concentrations of Abscisic Acid(ABA) on leaf tissue structure of Korla fragrant pear and lay the foundation for the cultivation and regulation of Korla fragrant pear. Using the paraffin section method, the leaf thickness, the epidermis thickness, the palisade tissue thickness and the sponge tissue thickness were measured; palisade spongy ratio, Cell Tightness(CT) and Cell Looseness(CL) were examined after treatments with exogenous ABA. Leaf thickness, leaf palisade spongy ratio and palisade tissue thickness increased significantly after exogenous ABA treatment compared with CK, while the effect on leaf epidermis was not obvious. The leaf thickness and palisade tissue thickness increased evidently after 70 mg · L~(-1) ABA treatment by 24.89% and 41.10%, respectively. The tissue structures of leaves were more compact, while CL was lower after 70 and 90 mg · L~(-1) ABA treatments. The effects of different concentrations of exogenous ABA could increase the leaf thickness, palisade tissue thickness of Korla fragrant pear and CT, reduced the thickness of spongy tissue and CL. Among those concentrations of exogenous ABA, the effect of spraying 70 mg · L~(-1) exogenous ABA was suitable for improving cold resistance of Korla fragrant pear.
2017年04期 v.24;No.69 25-30页 [查看摘要][在线阅读][下载 920K] [下载次数：26 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：14 ] - Sami Rokayya;
Several mechanical and physical properties of five apple cultivars(Black, Apricot, Jester, Big Ariane and Medium Ariane) had been estimated. The results showed that there were important significant differences among the cultivars in most of the parameters that were measured. Among the cultivars, Black cultivar had the highest fruit mass(207.65 g), followed by Big Ariane(188.34 g) and Medium Ariane(137.49 g). The actual fruit volume(cm~3) ranged from 61.77(Apricot) to 269.67(Black). The highest geometric, arithmetic, square and equivalent mean diameter values were observed for Big Ariane. The surface area and projected area of cultivars were between 14.53-69 cm~2 and 45.56-165.33 cm~2, respectively. The maximum coefficient of static friction was obtained on plastic followed by steel, iron and glass; the maximum coefficient of dynamic friction was obtained on glass followed by steel, plastic and iron.
2017年04期 v.24;No.69 31-39页 [查看摘要][在线阅读][下载 395K] [下载次数：15 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：16 ] - Wang Li-jun;Liu Yan;Liu Shuai;Sun Kai-jing;Wang Xin-ying;Zhang Guang-ning;Zhang Yong-gen;
This study was conducted to investigate the effect of Soybean Peptides(SPs) on ruminal fermentation and microbial diversity in vitro. Four levels of SPs supplements(0, 0.25%, 0.50% and 0.75% dry matter basis) were tested. p H, NH3-N, Neutral Detergent Fiber(NDF), Acid Detergent Fiber(ADF), Dry Matter Digestibility(DMD) and the Total Volatile Fatty Acid(TVFA) were measured at 6, 24, 48 h of in vitro mixed incubation the fluids. Microbial populations were determined at 24 h and Microbial Proteins(MCP) were determined at 24 and 48 h. The gas production after 48 h in vitro incubation presented linear growth(p<0.05) and the highest content was the level of 0.5% SPs(dry matter basis). NH3-N concentration reached the highest concentration with 0.75%(dry matter basis) at 48 h. p H linearly increased(linear, p<0.05) from 6 to 48 h. The digestion of DMD increased with increasing doses of SPs at 24 h. NDF and ADF linearly(p<0.01) decreased by adding SPs. The concentration of TVFA linearly increased(p<0.05) at 6, 24 and 48 h, and reached the highest concentration at the level of 0.75%(dry matter basis). SPs decreased(p<0.05) the molar proportion of acetate and propionate, respectively at 24 and 48 h. Acetat to Propionate ratio(A/P; linear, p<0.05) increased at 48 h, and reached the greatest value at the level of 0.75%(dry matter basis) at 48 h. The populations of rumen Ruminococcus flavefaciens(R. flavefaciens), Ruminococcusalbus(R. albus), Fibrobacter succinogenes(F. succinogenes), Butyrivibrio fibrisolvens(B. fibrisolvens), Streptococcus bovis(S.bovis), Ruminobacter amylophilus(R. amylophilus) and Succinimonas amylolytica(S. amylolytica) were analyzed based on the total rumen bacterial 16 S ribosomal deoxyribonucleic acid(r DNA). The relative abundance of R. flavefaciens and R. albus increased at 24 h, but the relative abundance of F. succinogenes decreased at this time. The incubation of SPs had no effect on the abundance of S. bovis and R. amylophilus. The relative abundance of B. fibrisolvens and S. amylolytica reached the greatest value(p<0.05) at middle doses of SPs inclusion at 24 h. The value of MCPs linearly increased(p<0.05) at 24 and 48 h. These results showed that SPs could improve in vitro fermentation and nutrient digestion of feed substrates, and had the ability to modulate the ruminal fermentation pattern by regulating the composition of functional rumen microbes. Hence, SPs might be a potential feed additive applied in the diets of ruminants.
2017年04期 v.24;No.69 40-52页 [查看摘要][在线阅读][下载 500K] [下载次数：24 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：20 ] - Li Zhi-yuan;Zhou Chun-shuang;Wang Zhe;Wen Xue-peng;Gao Xue-jun;
Bacillus lincheniformis is a representative probiotic, widely used in food, medicine and livestock industries and other industries. In this experiment, a strain of Bacillus lincheniformis was isolated and identified, which was used to ferment celluloserich substrate. The effects were analyzed. The experimental results showed that Bacillus lincheniformis had the capacity to degrade cellulose(32.8% was degraded) and less capacity to degrade hemicellulose(7.9% was degraded), which could not degrade ligin. The total protein contents in the products fermented by Bacillus lincheniformis with cellulose-rich substrate riched by 11.6%, compared with the fermented products with no cellulose-rich substrate, furthermore, the contents of Met, Lys and Leu riched by 14%, 17.5% and 4.1%, respectively. These results showed that Bacillus lincheniformis had the ability to degrade cellulose and it provided experimental data for further utilization.
2017年04期 v.24;No.69 53-60页 [查看摘要][在线阅读][下载 524K] [下载次数：32 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：20 ] - Luo Guo-xing;Liu Zhi-yang;Li Shuai;Zhang Jin-bo;Gao Ji-guo;Zhang Jie;
Vegetative Insecticidal Proteins(VIPs), a large family of insecticidal proteins, are produced from Bacillus thuringiensis(Bt) during the vegetative growth stage. VIPs represent the second generation of bio-insecticides that confer a wider insecticidal spectrum and have stronger activity. This work compared the geographical distribution of Bt strains and their vip3 genes in different climatic zones in China, the tropical(Hainan Province), subtropical(Guangxi Province) and temperate zones(Heilongjiang Province). A total of 156 Bt strains were isolated from 841 soil samples in Hainan Province tropical region, 356 Bt strains from 1 420 soil samples in Guangxi Province and 167 Bt strains from 1 010 soil samples in different geographical regions in Heilongjiang Province. Twenty-two out of 156 strains from tropical Hainan Province and two out of 356 from subtropical Guangxi Province were found to express vip3 genes, while vip3 genes were not expressed from temperate zone in Heilongjiang Province. Restriction Fragment Length Polymorphism(RFLP) was used to identify different types of vip3 genes that were within the same family and three fulllength vip3 genes were isolated. The genes cloned from Bacillus thuringiensis strain SL3 expressed in the transformed E. coli BL21 strain. Through SDS-PAGE, 88.6 ku insecticidal protein was expressed. The bioassays used two-instar larva of Lepidoptera insects(Spodoptera exigua and Agrotis ipsilon) were performed. The results of the bioassays showed that the protein strongly inhibited the body weight increasement on Spodoptera exigua and Agrotis ipsilon in a standard bioassay. Taken together, the results indicated that the distribution of Bt strains and vip3 genes had regional preference. Tropical and subtropical regions were the rich resources of Bt strains and vip3 genes compared with temperate region. These results would undoubtedly facilitate the studies of insecticidal proteins and expand the list of the pest-killing candidates to make fully use of the extremely rich microbial resources. The new vip3 genes isolated in the current study might also help resolve the emerging insecticidal resistance problems.
2017年04期 v.24;No.69 61-68页 [查看摘要][在线阅读][下载 844K] [下载次数：18 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：25 ] - Fang Jun-long;Yu Xiao-juan;Wang Rui-fa;Wang Run-tao;Li Peng-fei;Shao Chang-hui;
The grain production prediction is one of the most important links in precision agriculture. In the process of grain production prediction, mechanical noise caused by the factors of difference in field topography and mechanical vibration will be mixed in the original signal, which undoubtedly will affect the prediction accuracy. Therefore, in order to reduce the influence of vibration noise on the prediction accuracy, an adaptive Ensemble Empirical Mode Decomposition(EEMD) threshold filtering algorithm was applied to the original signal in this paper: the output signal was decomposed into a finite number of Intrinsic Mode Functions(IMF) from high frequency to low frequency by using the Empirical Mode Decomposition(EMD) algorithm which could effectively restrain the mode mixing phenomenon; then the demarcation point of high and low frequency IMF components were determined by Continuous Mean Square Error criterion(CMSE), the high frequency IMF components were denoised by wavelet threshold algorithm, and finally the signal was reconstructed. The algorithm was an improved algorithm based on the commonly used wavelet threshold. The two algorithms were used to denoise the original production signal respectively, the adaptive EEMD threshold filtering algorithm had significant advantages in three denoising performance indexes of signal denoising ratio, root mean square error and smoothness. The five field verification tests showed that the average error of field experiment was 1.994% and the maximum relative error was less than 3%. According to the test results, the relative error of the predicted yield per hectare was 2.97%, which was relative to the actual yield. The test results showed that the algorithm could effectively resist noise and improve the accuracy of prediction.
2017年04期 v.24;No.69 69-79页 [查看摘要][在线阅读][下载 733K] [下载次数：20 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：23 ] - Ebewore Solomon Okeoghene;
This study examined the adoption of herbicides by arable farmers in Edo State. It assessed the proportion of arable farmers using herbicides, level of use and factors affecting adoption of herbicides. Simple random sampling was used to compose a sample size of 556 respondents. Various descriptive and inferential statistics were employed in data analyses. The results showed that onehalf of the respondents used herbicides(27.9% regularly using herbicides), and most of the adopters used non-selective herbicide. Avalanche of factors, including education attainment, farm size and farming experience also affected the adoption of herbicides.
2017年04期 v.24;No.69 80-88页 [查看摘要][在线阅读][下载 408K] [下载次数：10 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：25 ] - Akeem Babatunde Dauda;Hassan Ishaq Ibrahim;Armayau Hamisu Bichi;Adenike Susan Tola-Fabunmi;
This study assessed the fish production, culture facilities, operations, water resource management and profitability of fish farming in Katsina State, Nigeria, with a view of understanding the status of aquaculture development in Katsina State. Data were collected using structured questionnaire administered to 35 out of the active 42 farms in Katsina State at the period and the data obtained were analyzed using descriptive statistics and linear regression. Among the respondents, 37.1% used concrete tank alone and another 37.2% used concrete tank with other types of culture facilities, 57.1% practised mono-culture techniques and 77.1% used stagnant renewal system as culture system. Management of water quality was done by majority(82.9%) with mere visual evaluation, while 68.6% did not use any forms of water treatment. Most of the farms(80%) depended on imported feed for feeding their fish and gross profits of ■7.29±1.81 and ■157.83±118.08 were obtained on fingerlings and adult fish, respectively. The tested explanatory variables were responsible for 45.4% change in profitability and profitability was found to be dependent on feeding cost(t=–3.38 and p=0.002) and size of fish at harvest(t=2.70 and p=0.011). The research findings established that fish farming in Katsina State was under developed.
2017年04期 v.24;No.69 89-96页 [查看摘要][在线阅读][下载 434K] [下载次数：61 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：19 ] -
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2017年04期 v.24;No.69 97-100页 [查看摘要][在线阅读][下载 228K] [下载次数：6 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：17 ] <正>Aims and Scope Journal of Northeast Agricultural University(English Edition)is a comprehensive academic journal on agricultural sciences sponsored by Northeast Agricultural University and distributed worldwide.It is a peer reviewed journal published quarterly and mainly publishes review and research articles that reflect the latest achievements on crop science,horticulture,plant protection,resource and
2017年04期 v.24;No.69 101页 [查看摘要][在线阅读][下载 657K] [下载次数：4 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：15 ]