Effect of tillage and fertilizer levels on wheat yield, nitrogen uptake and their correlation with carbon isotope discrimination under rainfed conditions in north-west Pakistan   总被引：2，自引：0，他引：2  

M. M. Iqbal  J. Akhter  W. Mohammad  S. M. Shah  H. Nawaz  K. Mahmood 《Soil & Tillage Research》2005,80(1-2):47-57

Appropriate cultural practices need to be determined for enhancing crop yields with low inputs under rainfed conditions. A field experiment was conducted to study the effect of tillage practices and fertilizer levels on yield, nitrogen (N) uptake and carbon (C) isotope discrimination in wheat (Triticum aestivum L.) grown under semi-arid conditions at three sites in north-west Pakistan: NIFA, Urmar and Jalozai. Two fertilizer levels, 60 kg N ha⁻¹+30 kg P ha⁻¹ (L1) and 60 kg N ha⁻¹+60 kg P ha⁻¹ (L2), were applied to wheat grown under conventional tillage (T1) and no-tillage (T0) practices. Labeled urea having 1% ¹⁵N atom excess at 60 kg N ha⁻¹ was applied as aqueous solution in microplots within each treatment plot. A pre-sowing irrigation of 60 mm was applied and during the growing season, the crop relied entirely on rainfall (268 mm). Biomass yield, N uptake and stable C isotope composition (δ¹³C) of plants were determined at maturity. Yield of wheat was improved by tillage at two sites (Sites 1 and 2), while at the third site yield was reduced by tillage as compared with the no-tillage treatment. At Sites 1 and 2, nutrient addition (L2, 60 kg N ha⁻¹+60 kg P ha⁻¹) increased the yield of all plant parts (straw, grain and root) in contrast to Site 3 where only grain yield was increased significantly. Maximum grain yield of wheat was observed with tillage under nutrient level L2 at all sites. Generally, the tillage treatment did not affect the N content in plant parts compared with no-tillage (T0) treatment at all three sites. However, fertilizer N uptake by wheat was variable under different fertilizer levels and tillage practices. Nitrogen derived from fertilizer (Ndff) for grain at Site 2 was higher in tilled plots but was not affected by tillage practice at the other sites. The C isotope (δ¹³C) values varied from −28.96 to −26.03‰ under different treatments at the three sites. The δ¹³C values were less negative indicating more effective water use at Sites 2 and 3 compared to Site 1. The C isotope discrimination (Δ) values were positively correlated with yield of wheat straw (r=0.578^*), grain (r=0.951^**) and root (r=0.583^*). Further, the Δ in grain had significant negative relationship (r=0.912^**) with Ndff (%). The tillage practice exerted a positive effect on yield, N uptake and plant N derived from fertilizer by wheat compared to no-tillage. The positive correlation of Δ with grain, straw and root yields and negative correlation with the Ndff (%) by wheat suggest that this value (Δ) could be used to predict these parameters. However, further studies on different crops under varied environmental conditions are necessary.  相似文献   

Understanding Interaction Patterns within Deep-Sea Microbial Communities and Their Potential Applications     

Muhammad Zohaib Nawaz  Raghul Subin Sasidharan  Huda Ahmed Alghamdi  Hongyue Dang 《Marine drugs》2022,20(2)

Environmental microbes living in communities engage in complex interspecies interactions that are challenging to decipher. Nevertheless, the interactions provide the basis for shaping community structure and functioning, which is crucial for ecosystem service. In addition, microbial interactions facilitate specific adaptation and ecological evolution processes particularly essential for microbial communities dwelling in resource-limiting habitats, such as the deep oceans. Recent technological and knowledge advancements provide an opportunity for the study of interactions within complex microbial communities, such as those inhabiting deep-sea waters and sediments. The microbial interaction studies provide insights into developing new strategies for biotechnical applications. For example, cooperative microbial interactions drive the degradation of complex organic matter such as chitins and celluloses. Such microbiologically-driven biogeochemical processes stimulate creative designs in many applied sciences. Understanding the interaction processes and mechanisms provides the basis for the development of synthetic communities and consequently the achievement of specific community functions. Microbial community engineering has many application potentials, including the production of novel antibiotics, biofuels, and other valuable chemicals and biomaterials. It can also be developed into biotechniques for waste processing and environmental contaminant bioremediation. This review summarizes our current understanding of the microbial interaction mechanisms and emerging techniques for inferring interactions in deep-sea microbial communities, aiding in future biotechnological and therapeutic applications.  相似文献   

Gibberellin producing Neosartorya sp. CC8 reprograms Chinese cabbage to higher growth     

Muhammad Hamayun  Sumera Afzal Khan  Abdul Latif Khan  Nadeem Ahmad  Yasmin Nawaz  Hasan Sher  In-Jung Lee 《Scientia Horticulturae》2011

Gibberellins production by soil fungi received little attention, although substantial work has been carried out on other growth promoting aspects of soil borne fungi. We investigated gibberellins production and growth promoting capacity of a novel fungal strain of Neosartorya, which was isolated from the roots of Chinese cabbage (Bassica rapa L. ssp. pekinensis). Fungal culture filtrates (CF) obtained from pure cultures of 16 endophytic fungi were bioassayed on Waito-C, in order to investigate plant growth promoting capacity of these fungi. The fungal isolate CC-8 induced maximum shoot length of Waito-C (13.0 cm) as compared to control treatments. In a separate experiment, the CF of fungus CC-8 significantly promoted plant length and biomass of Chinese cabbage. The fungal CF also increased endogenous bioactive GA₁ and GA₄ contents of Chinese cabbage. Gibberellin analysis of CF of CC-8 showed presence of both physiologically active and non active gibberellins in higher concentrations (GA₁, 1.42 ng/ml; GA₃, 5.93 ng/ml; GA₄, 11.36 ng/ml; GA₇, 3.25 ng/ml; GA₉, 0.79 ng/ml; GA₁₅, 1.18 ng/ml). The culture filtrate of CC-8 produced higher amounts of GA₃, GA₄, GA₇ and GA₉ than wild type Fusarium fujikuroi, a well known gibberellins producing fungus. The fungal isolate CC-8 was later identified as a new strain of Neosartorya species on the basis of traditional and advance molecular techniques.  相似文献   

Impact of urea and farm yard manure on nitrate concentration in soil profile and productivity of wheat crop     

Syed Adnan Mazhar  Muhammad Nawaz  Shahbaz Khan 《Journal of plant nutrition》2013,36(20):2683-2691

Abstract

During the last century, concerns about nitrate presence in the groundwater have tremendously increased worldwide, mainly because of its detrimental consequences on environment and human health. There are different factors contributing their past in nitrate pollution, farm manure is given due consideration. Knowing above facts, a field study was performed to check the effect of different farm yard manure (FYM) levels with urea on nitrate distribution in the soil profile and yield of wheat crop. The experiment was set out in a randomized complete block design, consisted of application of nitrogen at 125?kg ha^?1 from urea, 80?kg ha^?1 of N from urea +10 tons FYM ha^?1 and 20 tons FYM ha^?1 with three replications. Wheat (cultivar S7ehar-2006) was sown as test crop. Soil samples were examined to measure the nitrate concentration from four different depths (0–25, 25–50, 50–75, and 75–100?cm) after harvesting. Results showed that the straw yield, total biomass, spike length, and number of grains per spike and 1000-grain weight were significantly influenced by fertilizer strategies. All manure treatments significantly affected the infiltration rate and concentration of nitrate at different depths of the soil profile. Farm yard manure showed greater nitrate concentration up to 50?cm depth as compared to alone urea and combined application, while at the depth of 100?cm, combined application of urea and FYM showed a minimum concentration of nitrates than alone application of either urea or FYM.  相似文献   

Setting the net lower: A potential low-cost mitigation method to reduce cetacean bycatch in drift gillnet fisheries     

Jeremy J. Kiszka  Muhammad Moazzam  Germain Boussarie  Umair Shahid  Babar Khan  Rab Nawaz 《水产资源保护:海洋与淡水生态系统》2021,31(11):3111-3119

1. Bycatch is the most significant threat to marine megafauna (sea turtles, marine mammals, elasmobranchs, seabirds) worldwide, and the leading cause of the decline of several cetacean species. The bycatch issue in the Indian Ocean is poorly understood, but high bycatch levels in gillnet fisheries have been documented for the past two decades, in both small-scale and semi-industrial fisheries. Unfortunately, methods to reduce bycatch are often unavailable, financially non-viable or socially unacceptable to fishermen.
2. Using a network of trained boat captains in the tuna drift gillnet fishery in the Arabian Sea, targeted catch and bycatch data were collected from 2013 to 2017 off the coast of Pakistan (northern Indian Ocean). Two fishing methods using multifilament gillnets were used: surface deployment and subsurface deployment (i.e. headline of net set below 2 m depth).
3. Predicted catch rates for targeted species did not differ significantly between the two fishing practices, although a drop in tuna (6.2%) and tuna-like (10.9%) species captures was recorded in subsurface sets. The probability of cetacean bycatch, however, was 78.5% lower in subsurface than in surface sets.
4. Cetacean bycatch in tuna drift gillnet fisheries has the potential to be significantly reduced at a relatively low cost for fishers. However, further research with an appropriate sampling design and a large sample size is required to confirm the efficacy of the proposed mitigation method. The acceptability and adoption of subsurface setting by fishers also needs to be further investigated. Despite some limitations, this preliminary study also highlights the importance of crew-based observer data as an alternative source of data when observers cannot be deployed on fishing vessels.

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Early detection of the effects of compaction in forested soils: evidence from selective extraction techniques     

Muhammad Farrakh Nawaz  Guilhem Bourrié  Fabienne Trolard  Jacques Ranger  Sadaf Gul  Nabeel Khan Niazi 《Journal of Soils and Sediments》2016,16(9):2223-2233

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Allelopathic Potential of Soliva sessilis Ruiz & Pav. on Wheat     

Nawaz  Asma  Hussain  Zahid  Akhtar  Naveed  Hussain  Fida  Ullah  Naeem 《Gesunde Pflanzen》2022,74(2):477-486

Soliva sessilis (Burweed) is a winter annual weed found in wheat crop of Pakistan. It is thought to have an allelopathic effect on wheat crop. In this regard, an experiment was conducted in 2019 in the department of Weed Science and Botany at the University of Agriculture Peshawar, to assess the allelopathic potential of S. sessilis on various wheat varieties grown in Peshawar, Pakistan. Physiologically matured roots and leaves of S. sessilis were dried, ground and stored. Three common wheat varieties were selected for the research including Atta Habib, Pirsabaq-15, and Shahkar-13. The treatments of the experiment comprised of the aqueous extracts of the roots and leaves of S. sessilis, hot water extracts, methanol extracts, litter, and mulches. A mass of 5?g of S. sessilis was taken for the different extracts for 24?h, however, the methanol extract was kept for 48?h. The effect of the treatments was highly significant on wheat seed germination, radicle length, plumule length, fresh biomass as well as dry biomasses of the three tested wheat varieties. The variety Atta Habib was discovered as the most susceptible variety to the treatments of aqueous extracts, hot water extracts, and leaves’ litter. In contrary, the variety Pirsabaq-15 exhibited a remarkable increase in the various data collection parameters. The leaves of S. sessilis were observed more toxic as compared to the roots. The mulch of S. sessilis indicated stimulatory effect on the wheat varieties. For the interaction effect between treatments and varieties, the leaves and roots aqueous extract and their litter showed inhibitory effect. In conclusion, the leaves and roots of S. sessilis are potentiality allelopathic to wheat crop plants and further study is needed to assess the types of these allelochemicals present in the leaves and roots of the weed.

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芥菜型油菜野生及其衍生种质遗传多样性分析     

赵海菲  杨秀玲  余坤江  王天娅  晏伟  Aimal Nawaz Khattak  田恩堂 《中国油料作物学报》2022,44(1):57-62

芥菜型油菜是重要的油料作物和蔬菜,具有优良的抗旱、抗病和抗裂角等特性.本研究选用34份野生芥菜型油菜微核心种质及其衍生而来的51份新种质作为研究材料,采用305个ILP(intron length polymorphism,内含子长度多态性)标记对全部85份种质材料进行了聚类分析,将全部材料分为两个群,每个群内野生种质...  相似文献   

Identification and characterization of important sterile and maintainer lines from various genotypes for advanced breeding programmes of onion (Allium cepa)     

Rafiq Ahmad  Mahmood-ul- Hassan  Ghanan B. Akhtar  Sadia Saeed  Sabaz A. Khan  Muhammad Kausar Nawaz Shah  Nadeem Khan 《Plant Breeding》2020,139(5):988-995

Onion is one of the major vegetable crops in terms of production as well as consumption. In the current research, available onion genetic stock was evaluated to identify male-sterile lines and produce high-yielding F₁ hybrids for future breeding programmes. A mitochondrial DNA-based marker was mapped and correlated with phenotypic traits to isolate male-sterile plants. Based on the floral and pollen structure, nine putative male-sterile lines were identified. On the other hand, for nuclear marker identification at Ms locus, two sets of primers were used, one for Ms dominant allele and another for sterile and maintainer plants. Results revealed that 70% of open pollinated varieties (OPVs) possess plants with sterile cytoplasm coupled with genetic sterility at Ms locus, called sterile “A” line. Approximately 20% of plants in some genotypes were identified with normal (N) cytoplasm having recessive fertility gene at Ms locus, called maintainer “B” line. Based on the present findings, “A”, “B” and “R” (restorer line), future F₁ hybrid seed production systems in onion is discussed.  相似文献   

Gossypol‐induced fitness gain and increased resistance to deltamethrin in beet armyworm,Spodoptera exigua (Hübner)     

Muhammad Hafeez  Sisi Liu  Saad Jan  Bahar Ali  Muhammad Shahid  G Mandela Fernndez‐Grandon  Muhammad Nawaz  Aqeel Ahmad  Mo Wang 《Pest management science》2019,75(3):683-693

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