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1.
The residual effect of organic and mineral fertilizers on selected chemical properties of an Alfisol in the long term soil fertility trial established in 1950 at Samaru, Nigerian savanna was assessed. The trial was left fallow for fourteen years due to lack of funds. Topsoil was collected from plots that received three levels of cow dung （D）, nitrogen （N） and phosphorus （P） in all possible combinations. The soils were analyzed for selected chemical properties. Except for significant effect of applied P on available P, sole application of cow dung, N or P had no significant effect on all the measured soil properties. The interaction of D and P significantly affected the mean values of exchangeable Ca, Mg, K and ECEC in the range of 1.12-1.96, 0.62-1.11, 0.37-0.64 and 2.82-4.11 cmol/kg respectively. The most important results were the ability of the plot that received neither D nor P to significantly increase these parameters than the plots that received only one of the treatments. The results show that the fallow period has changed the effects of application of organic and mineral fertilizers on the soil chemical properties under continuous cultivation by modifying them towards those of a native savanna Alfisol.  相似文献   

2.
The effects of different tillage systems and poultry manure on soil physical properties, performance and nutrients in sorghum were studied for three years at Owo, southwest Nigeria. There was factorial combinations of herbicide-based zero tillage （ZT）, manual clearing （MC）, disc ploughing （P）, ploughing plus harrowing （P＋H） and ploughing plus double harrowing （P＋2H）, and two rates of poultry manure at 0 and 7.5 Mg ha^-1. Herbicide-based zero tillage and manual clearing reduced soil temperature and conserved more water than mechanized tillage techniques. Poultry manure reduced soil bulk density and temperature and increased soil water and porosity. There was a percentage decrease of leaf N, P, K, Ca and Mg concentrations, plant height, leaf area, stem girth, root dry weight, dry matter and grain yield in ascending order for herbicide-based zero tillage, manual clearing, ploughing, ploughing plus harrowing and ploughing plus double harrowing while percentage increases were recorded in a descending order for all the various combinations of tillage with poultry manure in that order. Poultry manure in combination with tillage increased dry matter and grain yield by 33.1 and 39.5%, respectively in comparison with tillage only. The manure-zero tillage methods increased dry matter and grain yield by 8% and 15%, respectively when compared with manure-mechanized tillage methods. Zero tillage or manual clearing in combination with 7.5 Mg ha^-1 poultry manure was most suitable for sorghum cultivation.  相似文献   

3.
This paper reviews results of some morphometric properties and chemical analyses of natural populations of the Cornelian cherry collected in the Vojvodina Province in 2008. Purpose of this study was the selection of the best genotypes for future breeding program until the final goal and that is standardizing Cornelian cherry cultivars. Chemical content has been found to depend on the genotype. Total sugar content in fruits ranged from 11.77% （CPC16） to 41.62% （BPC7）, vitamin C from 17.15 mg/100 g （APC8） to 42.30 rag/100 g of fresh fruit （APC2）, Ca pectat from 0.17% （APC6） to 2.52% （KC 1 ） and anthocyanin from 22.65 mg/100 g （APC4）to 96.30 rag/100 g of fresh fruit （BPC1）. Cornelian cherry fruits have an especially high content of minerals compared with other fruit species： the potassium content （in ppm） ranges from 2330 （APC6） to 11487 （APC4）, the calcium content from 33.80 （APC6） to 1307.70 （BPC1）, the sodium content from 22.82 （BPC8） to 273.48 （APC8）, the magnesium content from 10.20 （APC6） to 372.80 （APC8） and the iron content from 2.38 （KC2） to 14.40 （APCS）. The balanced content of nutrients, a wide range of food products made from the Cornelian cherry and an extremely high nutritional value make this fruit species a highly recommendable food item, especially if it comes from organic production.  相似文献   

4.
Cucumber is one of the important vegetables in many countries. Information about physical properties of cucumber is necessary for designing, grading, sorting and processing operations. In this study, some physical properties such as diameter, length, height, and weight of three varieties of cucumber （Green Gold, Dharwad, and Super Dominus） were measured. The results revealed that there was no significant difference （P〈0.01） in the density values of the studied varieties, but regarding other physical properties there were a significant difference （P〈0.01） among them. The average density for Green Gold, Dharwad and Super Dominus were 0.98, 0.95 and 0.94 g/cm^3, respectively. Green Gold cucumber had the highest diameter, volume, weight, flesh diameter, geometric mean diameter and sphericity. Dharwad and Super Dominus varieties with 15.49 cm length and 4.61 length to diameter ratio had the highest length and length to diameter ratio, respectively. Smallest skin thickness （1.48 cm） was for Super Dominus. Surface area of Green Gold, Dharwad and Super Dominus were 192.29, 192.4 and 131.2 cm^2. As well as there was a high and positive correlation between weight and volume in the studied varieties. There was a non-significant and low correlation （0.56） between diameter and length in Super Dominus. There was also a high and positive correlation between diameter and geometric mean diameter in all the varieties.  相似文献   

5.
Two variable charge soils were incubated with biochars derived from straws of peanut, soybean, canola, and rice to investigate the effect of the biochars on their chemical properties and Pb（II） adsorption using batch experiments. The results showed soil cation exchange capacity （CEC） and pH significantly increased after 30 d of incubation with the biochars added. The incorporation of the biochars markedly increased the adsorption of Pb（II）, and both the electrostatic and non-electrostatic adsorption mechanisms contributed to Pb（II） adsorption by the variable charge soils. Adsorption isotherms illustrated legume- straw derived biochars more greatly increased Pb（II） adsorption on soils through the non-electrostatic mechanism via the formation of surface complexes between Pb（II） and acid functional groups of the biochars than did non-legume straw biochars. The adsorption capacity of Pb（II） increased, while the desorption amount slightly decreased with the increasing suspension pH for the studied soils, especially in a high suspension pH, indicating that precipitation also plays an important role in immobilizing Pb（II） to the soils.  相似文献   

6.
The study area is located in Duhok and Sulaimania province in Kurdistan region, lraq. Study soils developed from parent material that has derived from limestone. Randomize, composed and disturbed surface soil samples were collected. The bulk soils were air dried, crushed and passed through 2 mm sieve. Standard methods were used for chemical, physical, geotechnical and mineralogical analyses of soil samples. The results indicated that the study soils texture were clay to loam clay, this texture was considered as suitable for ceramic and pottery industries as a result of increasing clay contents that ranged between 301 g/kg and 676 g/kg. Soil consistence depending on geotechnical properties increased the ability of study soils for resistance rapture and deformation. Existence the high amount of cementing agents in study soils such as organic matter, iron oxides and particularly total carbonate （247.2-308.8 g/kg） act to reduce the bad effect of the smectite minerals group （high shrinkage） in soils of study locations through increasing the resistance of these soils for rupture and deformation. The existing of Kaolinite, palygorskite and chlorite allows clay to be dried in ceramic and pottery industries without cracking from shrinkage. Study soils were different in their colors as a result of existence, different pigmentation materials that led to coloring soils with different colors in turn caused coloring of pottery and ceramic materials. Since, there are no available academic studies or researches about this subject in Kurdistan region in addition the clay pottery and ceramic sector still has a good market at the same time using this type of soils for arts, therefore, this study was conducted.  相似文献   

7.
The object of this study was to investigate the frictional properties （repose angles and friction coefficient） of Iranian sunflower seed and its kernel （Fandoghi, Azargol and Shahroodi） as a function of moisture content, size and variety. The static coefficient of friction were determined on five structural surfaces including aluminium, plywood, galvanized iron, polyethylene and rubber when moisture content varied between 3 and 14 % d.b. The obtained results showed that static coefficient of friction on five studied surfaces increase linearly as moisture content increase from 3 to 14% for both seed and kernel. Among the applied surfaces, rubber showed the highest value of friction coefficient for both sunflower seed and kernel followed by plywood, polyethylene, galvanized iron and aluminium. The obtained values of emptying and filling angles of repose increase linearly with an increase in moisture content. Furthermore, the values of empting and filling angles of repose for small sizes were higher than big sizes in all levels of moisture content for both seed and kernel. Also, the emptying angle of repose assumed higher values than the filling angle of repose for all varieties and categories.  相似文献   

8.
Some engineering properties of sunflower seed and its kernel, Shahroodi variety as a case study, were investigated at various moisture content levels （3-14% d.b.） for three size categories （large, medium and small）. With increase of moisture content from 3 to 14% d.b., all the main dimensions （length, width and thickness）, geometric mean diameter, porosity, true density, terminal velocity and static coefficient of friction increased while bulk density and rupture force for both sunflower seed and its kernel decreased for all size categories. The results showed that the highest value of static coefficient of friction for both seed and kernel was on the rubber surface, followed by plywood, polyethylene, galvanized iron, and finally aluminium surfaces. The seeds required less compressive force to dehull when loaded under the horizontal as compared to the vertical orientation. But for kernels, the trend was the opposite. Also, the compressive forces needed to initiate rupture of sunflower seed hulls were higher （47.1-94.72 N） than those required to rupture the kernel （8.5-13.4 N） in both orientations.  相似文献   

9.
Dairy proteins included sweet whey solids （SWS）, whey protein concentrate （WPC）, milk protein concentrate （MPC） or sodium caseinate （SC） at level of 10% by weight were extruded with corn, rice, oat flour and other ingredients in a twin screw extruder. The functional properties and textural of crispy balls snacks （CBS） have been studied. The results showed that different protein types were significantly affected on functional and chemical properties of extrudate. The bulk density of CBS-SC was the lowest due to the highest expansion, while CBS-WPC retained the most water in the product, whereas, the maximum value of water solubility index was obtained in the CBS-CWP. Results also showed that protein digestibility value of extrudates had higher than non-extruded products. Color analysis of CBS-SC and CBS-SWS products had the highest AE values （P ≤ 0.05）, whereas CBS-SWS was statistically higher than CBS-SC in rank. Also, it was noticed that CBS-SWS had the highest value of browning index. The hardness of all extrudates products was desirable for expanded crispy where ranged from 17.3 N to 12.18 N. Generally, MPC and SC incorporated with cereal flour had acceptable quality characteristics and improved significantly the functional and texture properties of crispy balls products.  相似文献   

10.
The objective of this study was to investigate the effect of moisture content, size and loading orientation on mechanical properties such as force, deformation and energy absorbed per unit volume for fracturing Iranian sunflower seed and its kernel （Azargol as a case study） under quasi-static loading. Sunflower seeds and their kernels were quasi-statically loaded in horizontal and vertical orientations with moisture content in three levels： 3%, 7% and 14%, and size category in three levels： small, medium and large. The obtained results showed that rupture force for both sunflower seed and its kernel decreased with increasing moisture content while the absorbed energy and deformation at rupture point increased for all size categories in both horizontal and vertical loading orientations. Also, seeds in the vertical orientation developed hull cracks at a higher level of force than those loaded in the horizontal orientation. However, for the kernels it was the opposite. In addition, the average forces required to cause kernel rupture were lower （11.64-39.9 N） than those required to rupture the seed （30.06-117.46 N） in both orientations. Seeds loaded in a vertical orientation absorbed more energy （87.67 mJ） prior to rupture than those loaded in the horizontal （46.60 mJ） orientation. However, for the kernels it was the opposite.  相似文献   

11.
Chlorination is usually an economical method for treating clogging in drip emitters during sewage application. Appropriate assessment of the responses of soil and crop is essential for determining an optimal chlorination scheme. During 2008 to 2009, field experiments were conducted in a solar-heated greenhouse for tomato drip irrigated with secondary sewage effluent, to investigate the influences of chlorine injection intervals and levels on soil chemical properties and nitrogen uptake. Injection intervals ranging from two to eight weeks and injection concentrations ranging from 2 to 50 mg L-1 were used. A salinity factor and a nutrient factor were extracted from the pool of the nine soil chemical constituents using factor analysis method. The results demonstrated that chlorination practices increased the residual Cl in the soil, resulting in an increased salinity factor, especially for the frequent chlorination at a high injection concentration. Chlorination weakened the accumulation of nutrients factor in the upper soil layer. Nitrogen uptake of the tomato plants also was inhibited by the increased salinity in the upper soil layer caused by high chlorination levels. In order to reduce the unfavorable effect on soil chemical properties and nitrogen uptake, chlorination scheme with concentrations of lower than 20 mg L-1 was recommended.  相似文献   

12.
Despite the fact that miombo woodland soils have significant implications in global climate change processes, few studies have been done to characterize and classify the soils of the miombo woodland ecosystem of Tanzania. The current study was carried out to map and classify soils of Kitonga Forest Reserve, which is a typical miombo woodland ecosystem, in order to generate relevant information for their use and management. A representative study area of 52 km2 was selected and mapped at a scale of 1：50,000 on the basis of relief. Ten representative soil profiles were excavated and described using standard methods. Soil samples were taken from genetic soil horizons and analyzed in the laboratory for physico-chemical characteristics using standard methods. Using field and laboratory analytical data, the soils were classified according to the FAO-World Reference Base （FAO-WRB） for Soil Resources system as Cambisols, Leptosols and Fluvisols. In the USDA-NRCS Soil Taxonomy system the soils were classified as Inceptisols and Entisols. Topographical features played an important role in soil formation. The different soil types differed in physico-chemical properties, hence exhibit differences in their potentials, constraints and need specific management strategies. Texture varied from sandy to different loams; pH from 5.1 to 5.9; organic carbon from 0.9 g/kg to 20 g/kg; and CEC from 3 cmol/（＋）kg to 24 cmol/（＋）kg. Sustainable management of miombo woodlands ecosystem soils requires reduced deforestation and reduced land degradation.  相似文献   

13.
J.  R.  Qasem 《农业科学与技术》2010,(6):104-120
Allelopathy importance and its application under field conditions are reviewed. Recent achievements in the field of plant protection are mainly considered and presented. Natural chemicals of potential use as pesticides, commercialized natural products of pesticidal properties are included. Reported plants of pest control properties, their targeted agricultural pests, formulations, methods of application and activity under field conditions are presented. Allelopathic plant species and implications on their use in the field, positive and negative impacts on cultivated crop species and agricultural pests are discussed. Some research difficulties and experimental methodology problems are mentioned. Prospects of allelopathy as a future strategy for pest management, development of eco-friendly biopesticides and importance for sustainable agriculture and recent developments in allelopathy research are discussed.  相似文献   

14.
Physicochemical properties of banana flour （BF） were studied in two varieties （Cavendish and Dream） and two stages of ripeness （green and ripe）. BF＇s were analyzed for pH, total soluble solids （TSS）, water holding capacity （WHC） and oil holding capacity （OHC） at 40℃, 60 ℃ and 80 ℃, color values L＊, a＊ and b＊, back extrusion force and viscosity. Physicochemical data were analyzed by Multivariate Analysis of Variance, discriminant analysis and cluster analysis. All statistical analyses showed that physicochemical properties of BF prepared from different variety and stage of ripeness were different from each other. Viscosity, WHC40, WHC60 and TSS were recommended methods for discrimination between banana flour prepared from the two varieties, whilst viscosity, WHC60 and WHC80 were suggested for differentiation of banana flour prepared using green and ripe banana.  相似文献   

15.
红黄壤茶园不同培肥模式的土壤理化效应   总被引：4，自引：0，他引：4  
通过长期定位试验,研究闽东地区红黄壤茶园不施肥(CK)、全量化肥(C)、(半量化肥+半量有机肥)(C1/2O1/2)、全量有机肥(O)、(全量化肥+豆科绿肥)(CL)及(半量化肥+半量有机肥+豆科绿肥)(C1/2O1/2L)等6种不同培肥模式下土壤理化性质的动态变化。结果表明:与CK模式相比,其他模式均能一定程度上改良土壤理化性状。其中,处理O和C1/2O1/2L的改良效益相对较佳,砂粒(0.05 mm相似文献   

16.
A literature survey and focused interviews with experienced agronomists and socio-economists from south, east, and southeast Asian countries were conducted to determine physical and economic relationships of cereal yields and N use, using partial factor productivity （PFP） and nitrogen （N） response functions, while considering the impacts of （N） and crop grain prices. The data were drawn from FAOSTAT, World Bank, and survey results from those countries. Rice has the greatest PFP-N （70 kg grain kg^-1 N）, wheat a moderate （57 kg grain kg^-1 N）, and maize the lowest PFP-N （52 kg grain kg^-1 N） at current application levels. At potential optimal N use rates, estimates for PFP-N were 26 kg grain kg^-1 N for maize, 25 kg for rice and 16 kg for wheat. Assuming a constant average PFP-N （30 kg grain kg^-1 N） for these cereals, it is estimated that 13 Mt N would be needed to meet a projected food demand by 2020 assuming no use of other additional inputs. Assuming a 20% increase in nitrogen use efficiency （NUE） to 36 kg grain kgl N, 10.6 Mt would be needed to meet the food demand, implying an annual growth rate in N use of 1.25%. It is concluded that economically optimal N rates are relatively insensitive to changes in prices of N and cereal grain. Key interventions to improve sustainable food security include increasing N fertilizer use, improving NUE, and reducing environmental impacts.  相似文献   

17.
The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.  相似文献   

18.
Medicinal plants provide an important source of cure since ancient time. Poor soil resources, scarce and saline water and the harsh environment limited the production of plants in the Arabian Gulf countries. This study aimed to investigate the production potential of rosemary （Rosmarinus officinalis L.） grown on different growth media under greenhouse conditions. Three growth media agricultural soil, compost and hydroponic system were used, whereas tuff （inert volcanic material） was used as substrate. The result indicated that the high salinity of the agricultural soil limited growth and oil yield in rosemary. Shoot height increased in 11 weeks, by 62%, 65% and 114% in plants grown in agricultural soil, hydroponic system and compost, respectively. Na content in plants grown in agricultural soil was significantly higher than in plants grown in the other treatment. Essential oil yield in plants grown in compost exceeded those in agricultural soil by 114%. Essential oil content （0.66%-1.5% w/w） and chemical constituents concentrations did not change significantly with growth media. The main constituents, more or less, are comparable to essential oils constituents reported from other countries. In comparison, better yields are obtained for individual components of the oils of plants grown under our green house conditions. This study demonstrated the great potential of commercial production of rosemary in the greenhouse without compromising the oil quality and oil yield.  相似文献   

19.
The objective of our study was to determine the effects of four types of fertilisers enrichments （manure potassic （K）, phosphatic （P）, phosphatic and potassic （PK） and nitrogenized, phosphated and potassic （NPK）） on chemical composition and dry matter in cassava （Manihot esculenta） organs （clone 1171） during harvest period. The pots experiment was laid out in randomised complete bloc design with five treatments and four replications. Water, nitrogen, potassium, phosphorus, sodium, total proteins and total lipids contents of the leaves, shoots and tubers were determined. After 9 months growing period, results showed that fertilizer types enriched with K, PK and NPK significantly increased the organic compounds contents of the leaves （P〈0.05）. Furthermore, fertilizers with high phosphorus content significantly increased the lipid contents of the leaves （25%）. Fertilizers enriched with NPK positively influenced the biomass partitioning in Manihot esculenta. Application of fertilizers enriched with NPK led to higher levels of total proteins in the leaves and tubers （70 mg g DM^-1 and 30 mg g DM^-1 respectively） compared to control （17 mg g DM^-1 and 9 mg g DM^-1 respectively）. These results help to demonstrate the value of these fertilizers enrichment to improve the chemical composition and dry matter partitioning of cassava.  相似文献   

20.
[目的]研究连续秸秆还田配施腐熟剂对土壤理化性状及水稻产量的影响。[方法]共设3个处理:常规施肥(对照)、常规施肥+秸秆全量还田、常规施肥+秸秆全量还田配施腐熟剂。利用秸秆失重率法研究秸秆还田配施腐熟剂对土壤理化性状和水稻产量的影响。[结果]与对照相比,秸秆还田配施腐熟剂、秸秆还田处理的有机质分别增加6.5、5.1 g/kg,有效磷、速效钾分别增加2.6、31.2和2.1、26.6 mg/kg;秸秆还田配施腐熟剂、秸秆还田处理的水稻产量分别较对照高出550、333 kg/hm2,增产6.37%、3.86%。[结论]秸秆还田配施腐熟剂能加速秸秆分解,改善土壤理化性状,有利于土壤养分的积累和水稻产量的提高。  相似文献   

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