免耕条件下秸秆还田对冬小麦-夏玉米轮作系统土壤呼吸及土壤水热状况的影响   总被引：12，自引：1，他引：11  

王维钰  乔博  Kashif AKHTAR  袁率  任广鑫  冯永忠 《中国农业科学》2016,49(11):2136-2152

【目的】研究免耕条件下秸秆还田对旱地冬小麦-夏玉米轮作系统土壤呼吸及土壤水热状况的影响。【方法】2011年10月至2014年9月,在陕西杨凌设置秸秆全量还田+施肥（S1F1）、秸秆全量还田+不施肥（S1F0）、秸秆半量还田+施肥（S1/2F1）、秸秆半量还田+不施肥（S1/2F0）、秸秆不还田+施肥（S0F1）、秸秆不还田+不施肥（S0F0）6 种不同耕作处理的3年定位试验,测定并分析不同耕作处理下土壤呼吸、土壤水热状况、作物产量、土壤耕作层有机碳含量的差异。【结果】在冬小麦生育期内,各处理土壤呼吸速率均呈先下降后升高再下降的趋势;在夏玉米生育期内,各处理土壤呼吸速率均表现为先升高后下降的趋势。同一生育期内各处理土壤呼吸平均速率及呼吸总量依次为S1F1＞S1/2F1＞S1/2F0＞S0F1＞S1F0＞CK,同种作物不同生育期之间,各处理土壤生育期呼吸总量有逐年降低的趋势。整个研究周期内,土壤温度的变化趋势与每月平均气温的变化趋势相似,不同处理在同一生育期内的土壤温度变化趋势相近,且各处理生育期土壤平均温度均随土壤深度的增加而降低;不同秸秆还田处理冬季土壤温度均高于对照,但生育期土壤平均温度均低于对照。土壤含水量随土壤深度的增加而降低,但受降雨影响,不同轮作周期之间的土壤含水量波动较大,各处理同一生育期的土壤平均含水量均表现为S1F0＞S1F1＞S1/2F0＞S1/2F1＞CK＞S0F1,且不同秸秆还田处理的土壤含水量与对照间的差异均显著（P＜0.05）;土壤温度能够解释土壤呼吸速率变化的32.5%-60.4%,土壤含水量能够解释土壤呼吸速率变化的38.4%-82.5%,不同土层深度间,5 cm土层的温度与土壤呼吸的拟合度性最高,而10-20 cm土层的含水量与土壤呼吸的拟合度最高。相同年份内,不同处理冬小麦和夏玉米产量均表现为S1F1＞S1F0＞S1/2F1＞S0F1＞S1/2F0＞CK,这个研究周期内,冬小麦产量逐年增加,夏玉米在前两季表现为增产,但受极端炎热天气的影响,第三季的产量明显降低。单季作物收获后,各处理同一土层深度的有机碳含量均表现为S1F1＞S1/2F1＞S1F0＞S1/2F0＞S0F1＞CK。且不同秸秆还田处理的土壤有机碳含量逐年升高。【结论】长期免耕秸秆还田能够有效降低农田土壤碳排放、提高农田土壤水分利用率及冬季土壤温度、提高作物产量及土壤有机碳含量。不同秸秆还田处理间以S1F0处理的效果最优。  相似文献   

QTL mapping for salt tolerance at seedling stage in the interspecific cross of Gossypium tomentosum with Gossypium hirsutum     

George Oluoch  Juyun Zheng  Xingxing Wang  Muhammad Kashif Riaz Khan  Zhongli Zhou  Xiaoyan Cai  Chunying Wang  Yuhong Wang  Xueyuan Li  Heng Wang  Fang Liu  Kunbo Wang 《Euphytica》2016,209(1):223-235

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Relationship between rhizosphere acidification and phytoremediation in two acacia species     

Abbas  Ghulam  Saqib  Muhammad  Akhtar  Javaid  Murtaza  Ghulam  Shahid  Muhammad  Hussain  Amjad 《Journal of Soils and Sediments》2016,16(4):1392-1399

Purpose

Phytoremediation is the most sustainable and economical strategy for reclamation of the salt-affected soils. In order to investigate the relationship between phytoremediation and rhizosphere acidification, two experiments (greenhouse and field) were conducted using two acacia species viz. Acacia ampliceps and Acacia nilotica.

Materials and methods

In greenhouse experiment, both the species were exposed to 100 and 200 mM NaCl concentrations in solution culture. The release of organic acids from plant roots was determined after 14 and 28 days of the salt treatment. Shoot and root ash alkalinity was determined after harvesting the plants. In field experiment, both the species were grown on a saline sodic soil for 2 years. After every 6 months, plant growth data were recorded and soil samples were collected from different soil depths for physicochemical analyses.

Results and discussion

The results of greenhouse study indicated higher rhizosphere acidification by A. ampliceps than A. nilotica in terms of release of citric acid, malic acid, and tartaric acid along with ash alkalinity. The comparison of both the species in the field indicated higher amelioration in the soil properties like pH_s, EC_e, SAR, bulk density, and infiltration rate by A. ampliceps than A. nilotica.

Conclusions

It is concluded from these studies that A. ampliceps is more suitable species than A. nilotica for the phytoremediation of the salt-affected soils due to its higher rhizosphere acidification potential.

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Maize production under risk: The simultaneous adoption of off-farm income diversification and agricultural credit to manage risk     

Shoaib Akhtar  Gu-cheng LI  Adnan Nazir  Amar Razzaq  Raza Ullah  Muhammad Faisal  Muhammad Asad Ur Rehman Naseer  Muhammad Haseeb Raza 《农业科学学报》2019,18(2):460-470

Farmers in Pakistan continue to produce maize under various types of risks and adopt several strategies to manage those risks. This study is the first attempt to investigate the factors affecting the concurrent adoption of off-farm income diversification and agricultural credit which the farmers use to manage the risk to maize production. We apply bivariate and multinomial probit approaches to the primary data collected from four districts of Punjab Province in Pakistan. The results show that strong correlations exist between the off-farm diversification and agricultural credit which indicates that the use of one risk management strategy leads to another. The findings demonstrate that education, livestock number, maize farming experience, perceptions of biological risks and risk-averse nature of the growers significantly encourage the adoption of diversification as a risk management tool while farm size inversely affects the adoption of diversification. Similarly, in the adoption equation of credit, maize farming experience, farm size, perceptions of price and biological risks and risk attitude of farmers significantly enhance the chances of adopting agricultural credit to manage farm risks. These findings are important for the relevant stakeholders who seek to offer carefully designed risk minimizing options to the maize farmers.  相似文献   

Genotypic variation in rice for grain yield and quality as affected by salt-affected field conditions     

Muhammad Zahid Mumtaz  Muhammad Saqib  Ghulam Abbas  Javaid Akhtar  Zia-ul Qamar 《Journal of plant nutrition》2018,41(2):233-242

A field experiment was conducted under two natural field conditions at the Research Farm (normal soil) and Proka Farm (salt-affected soil) of The Institute of Soil and Environmental Sciences (ISES), University of Agriculture, Faisalabad, Pakistan, to evaluate the performance of 11 rice genotypes in normal and salt-affected conditions. The experiment was laid out in randomized complete block design (RCBD) with three replications. The gas exchange attributes were measured at vegetative stage whereas the grain and straw yields and the yield components were recorded at maturity. After harvesting, the ionic parameters including sodium (Na⁺) and potassium (K⁺) were determined. Afterward, grain quality in terms of length, width, milling recovery, broken fraction, and chalkiness was also determined for the selected genotypes. Salt-affected conditions adversely affected the physiology, yield, and quality of the tested genotypes. The genotypes KS-282 followed by Shaheen Basmati showed significantly higher photosynthetic rate, transpiration rate, and stomatal conductance under both normal and salt-affected conditions, whereas the genotypes 99404 followed by 99417 showed minimum values of gas exchange attributes. The grain and straw yields were the highest in the case of KS-282 at both sites, whereas the lowest grain and straw yields were observed in the case of 99440 followed by 99417 under both normal and salt-affected conditions. Regarding the quality attributes, Super Basmati produced longer grains but with higher broken fraction and lower milling recovery, whereas the reverse was observed in the case of KS-282.  相似文献   

Antibody Prevalence and Risk Factors for Toxoplasma gondii Infection in Women from Multan,Pakistan          下载免费PDF全文

M. M. Nazir  M. Akhtar  A. Maqbool  A. Waheed  M. A. Sajid  M. A. Ali  M. Oneeb  M. A. Alam  A. N. Ahmad  N. Nazir  S. Fatima  D. S. Lindsay 《Zoonoses and public health》2017,64(7):537-542

Toxoplasma gondii infections are prevalent in humans and warm‐blooded animals. Maternal infections during pregnancy may have devastating consequences for transplacentally infected neonates. This study was conducted to examine the seroprevalence of antibodies to T. gondii in pregnant women of childbearing age and determine risk factors associated with pregnancy history, pet ownership, social and cultural factors at Nishtar Hospital, Multan. Samples were collected from 403 women and examined using a commercially available enzyme‐linked immunosorbent assay (ELISA). The overall prevalence of antibodies to T. gondii was 17.6% (71) in the 403 samples collected from women. Antibodies to T. gondii were present in 19.4% (45) of 232 pregnant women and 15.2% (26) of the samples from 171 non‐pregnant women. This study identified miscarriage history, pet ownership, type of residence, marital status, source of drinking water and eating habits as significant (P < 0.05) risk factors associated with the presence of antibodies to T. gondii infection. Seroprevalence was not significantly different (P > 0.05) in women from different ethnic groups based upon lifestyle and culture.  相似文献   

Effect of waste water and fly ash application on physiological determinants,yield, and heavy metal contents of yellow mustard (B. campestris cv. P. Gold)     

Seema Sahay  Saba Iqbal  Farha Ashfaque  Akhtar Inam 《Journal of plant nutrition》2017,40(12):1710-1727

A pot experiment was conducted to study the comparative effect of waste water (WW) and ground water (GW) alone and along with different nitrogen (N), phosphorus (P), and potassium (K) combinations (N₀P₀K₀, N₄₀P₁₅K₁₅, N₆₀P₃₀K₃₀, N₈₀P₄₅K₄₅) together with different levels of fly ash (FA) (FA₀, FA₁₀, FA₂₀), to obtain a suitable combination of fertilizers, FA and water based on the growth, physiology, yield, and heavy metal contents of Brassica campestris cv. Pusa Gold. Results revealed that WW irrigation proved beneficial over GW. All the parameters increased in both levels of FA₁₀ and FA₂₀ along with three doses of NPK but FA at 20 t ha^?1 proved better. The effect was more efficacious with both wastes together which makes NPK optimum at N₆₀P₃₀K₃₀ instead of N₈₀P₄₅K₄₅ treatment combinations and thereby lowered input of fertilizers. Therefore, utilization of these wastes may be recommended for the purpose of irrigation, soil amendment, and as a source of nutrients in augmenting the mustard yield.  相似文献   

Performance of mono‐sex tilapia (Oreochromis niloticus) in rice field with different ditch size          下载免费PDF全文

Md. Akhtar Hossain  Md. Anisur Rahman Mridha  Abul Kalam Md. Azad Shah  Md. Nahiduzzaman  Md. Sharif Uddin 《Aquaculture Research》2015,46(8):1891-1901

The effects of ditch size on growth and production of mono‐sex tilapia, Oreochromis niloticus in rain fed concurrent rice–fish system were technically and economically evaluated for a period of 4 months. Three different ditch sizes were tried: 5%, 10% and 15% of the total cultivable rice field. The fish fingerlings stocking density (5000 ha^?1) and management practices were similar in all plots. The water temperature, dissolve oxygen, pH, Secchi disc visibility, ortho‐phosphate, ammonia nitrogen and alkalinity were found to be in the range of 31.5–31.9°C, 5.10–5.27 mg L^?1, 7.56–7.62, 34.81–35.41 cm, 0.88–0.96 mg L^?1, 0.014–0.021 mg L^?1 and 66.23–69.76 mg L^?1, respectively, and all the values were found suitable for tilapia fish farming. Sediment organic matter, available nitrogen and phosphorous were increased significantly (P < 0.05) in all plots after cultivating the fish. Larger ditch size (15% of the total land area) resulted in significantly (P < 0.05) higher specific growth rate, survival and fish production compared with the smaller (5%) and medium (10%) ditch sizes. However, significantly (P < 0.05) higher net income and benefit–cost ratio were obtained in medium ditch size with the values of 2.6% and 3.6% higher than the smaller and larger ditch sizes respectively. It is concluded that rice–fish farming in a rain fed ecosystem of Bangladesh with medium ditch size and stocking density of 5000 ha^?1 mono‐sex tilapia can achieve better economic return.  相似文献   

Histomorphological changes in digestive tract of golden mahseer (<Emphasis Type="Italic">Tor putitora</Emphasis>) during different developmental stages     

Prakash Sharma  M. S. Akhtar  A. K. Singh  Partha Das  Debajit Sarma 《Fish physiology and biochemistry》2016,42(6):1681-1698

Histomorphological changes in digestive tract of golden mahseer (Tor putitora) were examined in larvae [starting from hatching to 45 days post-hatching (dph)], fry, fingerling, and adult. Digestive tract appeared during hatching, on the dorsal side of yolk sac, as a straight tube with a narrow lumen. Mouth opening and appearance of liver and pancreas were observed at 2 dph, and subsequently anal opening, appearance of goblet cells in esophagus, and posterior intestine were evident at 3 dph. The remodeling of oral cavity in terms of epithelial stratification, appearance of taste buds, and goblet cells were observed in a window of 4–5 dph. Intestinal folding was found to be initiated at 8 dph. From 12 to 45 dph, thickening of oral and esophageal mucosal/extramucosal layers, increase in intestinal folding, increases in the density of goblet cells in entire gut were observed. Within the same time window, other histological changes such as disappearance of vacuoles in liver, and abundance of zymogen granules in pancreas were also observed. Supranuclear vesicles in mid-to-posterior intestine were found to be prominent from first feeding to 45 dph; however, this phenomenon was no longer evident in fry and fingerling. Overall, the increase in intestinal folding and complexity of extramucosal layer were found to be continuous from the first appearance to adult, and this inferred the fact that the nutritional physiology, in terms of digestion and assimilation, progressively changes throughout the life stages of golden mahseer. Findings of this study will, therefore, help in preparing diets for different life stages of this fish, and in addition, the present information widens the understanding of digestive physiology of golden mahseer.  相似文献   

The phytoplasma disease ‘mung bean phyllody’ is now present in Pakistan     

K. P. Akhtar  M. Dickinson  J Hodgetts  G. Abbas  M. J. Asghar  T. M. Shah  B. M. Atta  M. Ahmad  M. A. Haq 《Plant pathology》2010,59(2):399-399

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