تقرير عن الزراعة بالانجليزي
تقرير عن الزراعة بالانجليزي
ترجمة الزراعة بالانجليزي بالعربي – ترجمة عربية لكلمة agriculture
الزراعة المائية بالانجليزي
الزراعة بالانجليزي
كلية الزراعة بالانجليزي
وزارة الزراعة بالانجليزي
شوكة الزراعة بالانجليزي
اسماء ادوات الزراعة بالانجليزي
ادوات الزراعة بالانجليزي
مديرية الزراعة بالانجليزي
تقرير عن الزراعة بالانجليزي
Farming Systems on Soil Properties
1- Introduction :
The use of organic amendments for improving the properties and productivity of soil resource base was a long-standing agronomic practice through the last two centuries in the Arab Region, especially under irrigation conditions. By the middle of the last century, the use of mineral fertilizers of individual and combined macro and micro nutrients gained significant momentum to achieve high rates of agricultural production from the dominant soil resources of poor fertility status and fragile soil properties. Such trend was driven by the urgent need to meet the demands of ever-increasing population with enhanced consumption rates due to progressive economic conditions and improved living standards. The introduction of high yielding crop varieties also enhanced the application of higher rates of mineral fertilizers.
As irrigated lands in the Arab Region contribute more than 70% of the produced agricultural commodities, progressive expansion in irrigation of reclaimed desert lands occurred in many countries of the Region such trend was accompanied by the decline of the use of natural organic amendments and the expansion of the use of chemical fertilizers and agricultural chemicals under extensive agricultural practices and varied farming systems. The use of synthetic conditioners, as well as, processed urban wastes were gradually increased. Field application of intensive rates of mineral fertilizers, agricultural chemicals and organic amendments of non-traditional sources caused apprehensive concerns pertinent to soil and water pollution and the potential health hazards for humans and animals consuming polluted agricultural products. Such concerns are presently governing qualities and specifications of food and feed commodities, marketing potentials, agricultural exports and imports under dominating world trade regulations. These concerns brought back the interest in organic farming practices to improve and develop the poor soil properties, on one hand, and secure the safety of the environment and the produced agricultural commodities on the other. The present paper will deal with the impact of organic farming on the soil properties in the region under varied agronomic practices and related farming system conditions.
2- Basic Characteristics of Soil Resources :
The land resource base of the Arab Region has been developed under varied conditions of aridity, physiographic features and types of parent materials. These factors have great bearings on the distribution and basic characteristics of the main soil types in the Arab Region. The prevailing climatic conditions are hyper arid, arid and semi-arid conditions with very limited areas that could be considered as sub-humid. Hyper-aridity and aridity prevail over the greater majority of the total area of the Region.
Total arable lands represent a small percentage (14.5%) of the total area of the Region. The presently cultivated areas represent less than one third (29.0%) of the total arable lands while irrigated lands represent about 20.1% of the cultivated areas Fig. (1).
The majority of cultivated lands in the Region are characterized by inferior soil properties due to poor soil development processes and varied constraints. Adverse impacts on the physical, chemical, biological and nutritional soil properties are dominant in the Region. Constraints of the soil physical properties include weak soil structure, coarse textural classes, inferior soil-water parameters including low water holding capacity and narrow range of available water. Soils with calcareous nature suffer from surface crusting, impaired soil drainage, formation of soil layers of varied compaction and lower filteration. Constraints of chemical soil properties include low CEC, dominance of Calcium and Magnesium, very low content of organic matter, limited supplying power of most nutrients especially available N due to low N content, immobilization of Phosphorus due to dominance of Ca, as well as, the low availability of most micronutrients including Fe, Zn, Mn and Cu due to alkalinity of soil reaction, impact of soil carbonate content, low organic matter content and other factors. Other constraints of chemical properties include development of soil salinity and sodicity due to water logging and impaired drainage. The presence of high soil gypsum content have serious adverse impacts on the physical and chemical soil properties.
Low soil moisture regime, low nutrients and energy sources in most soils of the region lead to low population of soil organisms which in turn cause low soil biological activities.
The varied combinations of the constraints referred to cause impaired soil productivity with adverse impacts on the quantities and qualities of the produced agricultural commodities. In addition, such constraints and inferior soil properties lead to low soil resilience, i.e. rapid response to soil management practices, as well as, high susceptibility to factors of degradation including erosion processes by wind and water, loss of productivity and enhanced pollution hazards. The varied constraints of soil properties referred to in addition to the introduction of high yielding varieties and the previously mentioned socio-economic implications are conducive to over use of fertilizers and agriculture chemicals which invariably leads to soil degradation, and pollution with added adverse impacts on the quality of agriculture commodities produced which present serious limitation to world trade and export-import relations for the countries of the Arab Region.
As pointed out earlier, the poor fertility, fragile and limited arid soil properties caused a rapid surge of the consumed mineral fertilizers and agricultural chemicals to increase productivity of reclaimed and irrigated desert areas, as well as, to meet the requirements of introduced high yielding varieties. Hamissa and El-Mowelhi (1989) pointed out the ever-increasing total and nitrogen fertilizers consumed in Egypt over a period of 15 years as reported by FAO (1994) (Fig 2). The data showed that total fertilizer consumed increased by 69% while the increase in N-fertilizers consumed was 77% in 1994 as compared to 1980. They added that consumption of fertilizers per hectare of the cultivated area in Egypt was ten times the average rate/hectare for the whole world.
Nitrogen fertilizer efficiency of applied N-fertilizers to varied crops was reported to be in the range of 23.0 – 53% Abdel-Monem et al. (1995) and (1997). Losses from applied Nitrogen to crops in Egypt was found to be very high especially under the conditions of coarse textured soils and flooded systems. Among the factors contributing to losses of applied nitrogen mainly through leaching, as well as, denitrification and volatilization losses were found to be related to the rate and timing of application, type of fertilizer added and soil properties.
3- Impacts of Organic Amendments on Arid Soil Properties :
The impacts of organic amendments on arid soil properties is highly significant in ameliorating and improving many of the diversified soil properties including the physical, chemical, biological and nutritional ones. Such impacts were proven by a large number of investigations that were carried out in the Arab Region, as well as, many arid and semi-arid areas of the world. The following is a summary of the beneficial impacts on arid soil properties supported by the results of recent investigations and measured parameters.
The first significant impact of application of organic amendments is to enhance the very limited soil organic matter content which is considered to be one of the important indicator of desert soil development. El Bagouri et al. (1988) and Hashem et al. (1992) reported that application of organic amendments through four years to calcareous and sandy soils enhanced the OM content of virgin soils by several folds based on the type of organic amendments, combinations and rates of application.
Products of advanced decomposition of organic amendments and humus complex compounds in addition to formation of clay-organic complexes contribute considerably to increase the soil cation exchange capacity CEC through the presence of functional groups including amino, carboxyl, phenolic and hydroxyl groups. Saber (1997) Beheiry et al. (1997) and (2002) reported doubling the cation Exchange capacity over four years of a sandy loam calcareous soil.
Application of appropriate organic amendments to the plow layer improve the tillage of the soil and contribute to curtail surface crusting thus improving crop germination in calcareous soils. Organic amendments were found also to contribute to the formation of medium and fine soils pores which improves aeration of the root-zone, as well as, contribute to enhance water holding capacity of the coarse textured calcareous soil which lead to enhanced Water Use Efficiency (WUE). Awadalla et al. (2002) found that application of composted town refuse and farmyard manure to sandy and calcareous sandy loam soils reduced infiltration rate from 28.8 to range of 15.3 – 16.5 cm/hour. WUE was increased by a range of 77 – 130% according to applied treatments of single, combined applications and initial soil properties.
Application of organic amendments significantly improve several soil physical properties. Such impacts are illustrated by the findings of El-Sersawy (2002) who found that application of town refuse compost and farmyard manure mixed with bio fertilizers to a highly calcareous medium textured soil in varied treatments led to the following, compared to the control, the treatments reduced bulk density by 15.0%, penetration resistance by 39.0%, increased total porosity by 21.0% and encouraged formation of medium and fine pores.
Similar improvement of soil physical properties due to application of organic amendment treatments which led to enhanced leaching of the salt content of a calcareous sandy loam under conditions of saline groundwater irrigation at Ras-Sudr Experimental Station, Desert Research Center. Soil EC was reduced by 4 EC units, which in turn significantly increased the wheat yield expressed as grain and straw.
Contributions of varied organic manure and composted crop residues significantly contribute to the soil fertility and its nutrients supplying power. These amendments contributes to macro and micro nutrients cycles in the soil, allow a significant portion of the nutrients especially Nitrogen and Phosphorus and micronutrients removed by the growing plants to be returned to the soil where it would be available for the following crops. The presence of these nutrients in slowly decomposed and nutrients release help conserve, these nutrients and significantly reduce its rapid leaching from the root zone especially the highly mobile nitrates under the conditions of course textured arid soils with rapid infiltration rates. Saber (1997), Beheiry et al. (1997) and Awadalla et al. (2002).
Many other investigations could be reported, however, the reported recent ones is useful to report measured parameters confirming the varied beneficial impact of organic amendments in improving inferior soil properties of arid and semi-arid regions.
تقرير عن الزراعة بالانجليزي
تقرير عن الزراعة بالانجليزي
ترجمة الزراعة بالانجليزي بالعربي – ترجمة عربية لكلمة agriculture
الزراعة المائية بالانجليزي
الزراعة بالانجليزي
كلية الزراعة بالانجليزي
وزارة الزراعة بالانجليزي
شوكة الزراعة بالانجليزي
اسماء ادوات الزراعة بالانجليزي
ادوات الزراعة بالانجليزي
مديرية الزراعة بالانجليزي
تقرير عن الزراعة بالانجليزي