Soil properties and characteristic in Kuwait for agricultural development

Symposium no. 20 Paper no. 1507 Presentation: poster Soil properties and characteristic in Kuwait for agricultural development ABDAL Mahdi and SULEIMAN Majda Arid Land Agricultural Department, Kuwait Institute for Scientific Research, Kuwait Abstract The soil of Kuwait is sandy in texture with little organic matter and scarce plant nutrients to support plant growth and development. Over-grazing and vehicle movement through the desert soil enhanced soil erosion and mobility. Most of soils are shallow in depth from continuous wind erosion and the lower calcareous layers that appear on the topsoil. Soil water holding capacity is low (7) with high infiltration rate (50-100 cm h -1 ) and the soil surface area is small due to coarse texture and little organic material (<0.1). Evaporation is high (3,000 mm y -1 ), particularly in the summer periods and rainfall is limited (100 mm y -1 ). Improvement of Kuwait soils for agricultural development and urban landscape requires soil management and enhanced capabilities for plant growth and development. Soil fertility and nutrients application can be improved through continuous soil analysis and plants trials in various soil adaptations. Soil water holding capacity can be enhanced with soil conditioners and periodical application of organic matter. The utilization of different soil mulches and the plant residual application should control the high evaporation rate and decrease soil infiltration. The paper discusses the soil properties in Kuwait and various methods of soil improvement for agricultural development and urban landscape for greenery in arid environment with emphasis in soil capability and soil fertility enhancement. Keywords: sandy, organic, nutrient, grazing, erosion, calcareous, infiltration, evaporation, capability, analysis, fertility Introduction Soils of Kuwait are mostly sandy with limited organic matter, having very low contents of plant nutrients and high amounts of calcareous materials. The soils water holding capacities are very small, soil water evaporation is very high particularly in the summer season and the infiltration rates are very high (Abdal and Al-Qallaf, 1993). Agricultural production in arid environment of Kuwait faces many obstacles and problems; due to limitation of water resources and soils low nutrients contents. Farmers mostly grow vegetables and forage crops for local consumption. The yields of most crops are low and the qualities are inferior. High amounts of irrigation water resources are utilized for minimum crop production. Farmers usually apply animal manure as organic matters to improve soil productivity. Fertilizer application in Kuwait is practiced without referring to any scientific findings related to soil fertility or crops nutrients requirements. Most of the fertilizer are applied by old traditions and/or other countries soil recommendations. The crops response is minimum because of quantities are not scientifically recommended and interference of the high amounts of calcareous materials within the soils profiles. Calcareous soils of Kuwait interact with plant 1507-1

nutrients applied to the soil within soils solutions. Most of the macro-nutrients and the micro-nutrients generally fix with calcium cation. The quantities of calcareous materials within the soils solution in Kuwait as in Table 3 are enormously high and practically whatever fertilizers added to the soils are fixed within the soil layers. Understanding soils property of arid land of Kuwait is very essential to improve soil capabilities and plant's growth and development. Large amounts of fertilizer and soil conditioners can be lost without the recognizing calcareous soils contents interaction with added materials. Improving soil condition in arid area of Kuwait can be accomplished by applying the correct amounts of plants nutrients to a particular soil needed by specific plant, reduction in soil alkalinity by acidic soil conditioners, usage of organic matters in corrected amounts, analyze soils regularly and understand the soil potential (Abdel Rahman et al., 1996). Various organic matters sources are obtainable in Kuwait that can be used to improve soils capabilities. Different agricultural industries chiefly in dairy; poultry; sheep; and camel husbandry s produces large amounts of manure that can be utilized as organic matters to improve soil properties (Larney and Janzen, 1996). Meanwhile, enormous quantities of municipal wastes are produced within the state that can be converted to beneficial materials for agricultural production. Large amounts of municipal waste are buried in huge limited land that can be utilized as organic matters for crop production and soil improvement. Municipal waste in Kuwait can be converted to good organic matter for soil conditioning and plant growth and development. Tremendous benefits can be achieved by the utilization of municipal organic waste management to improve soil fertility and reduction of land use for burying the waste. The paper discusses the benefits of organic use in various soils to improve soil fertility and soil tilth in various locations in Kuwait. Materials and Methods Various soil samples were collected from different depths (0-2, 0-5, 5-10, 10-15 cm) from three locations in Kuwait. The soils were treated by organic waste application in various time intervals (0, 20, 40 years). Three soils were compared in Kuwait for the effects of organic matters application with duration of time. The duration were from zero time application, twenty years time application and forty years time application of organic matter The samples were subjected for physical and chemical analysis to compare soils improvements and soils reactions with organic matter application. Samples were examined for soils bulk densities, water retention, water need for irrigation, texture, organic matter contents, macro and micro elements contents. Results and Discussion The application of organic matter has significant effect on soils bulk densities, particularly after forty years applications. Organic matter application improves soil tilth by decreasing soils bulk densities (Table 1). Sandy soils usually have high bulk densities, the addition of organic matter increase soil surface area (Kamau et al., 1996). Soils water holding capacities in both points, field capacities and wilting points, were significantly different among three soils. At field capacities soils water retention increased more than seven folds at twenty years of organic matter application, at the same time the soil water retention for forty years of organic matter application increased ten folds (Table 1). Improvement soils water holding capacities is a very important 1507-2

factor for crop production in arid environment. Since water is very limited for agricultural production and soils surface areas are very small. The use of organic matter in Kuwait did improve soil water retention significantly. Table 1 Effect of organic matter contents on soils physical conditions. Duration Bulk Density g/cm3 Field Capacity Wilting Points Texture Carbon Years 0 1.700 01.910 0.550 Sand 1.003 20 1.670 14.360 2.810 Loamy Sand 2.108 40 1.330 20.960 4.930 Loamy Sand 3.080 Micronutrients deficiency in Kuwait can be noticed in many plants leaves coloring or chlorosis and stunt growth. The high contents of calcareous materials within soils profiles interfere with the availability of micronutrients to the plants' roots. Organic matter's applications improve soil contents of micronutrients and plant's growth and development (Dierolf et al., 1997). Significant differences were noticed in soils total contents of micronutrients elements (Fe, Mn, Zn, B, and Cu) in the three treated soils with organic matter (Table 2). Iron contents through all soils profiles distinctively are different in all three treatments of organic matter application. Immense increases of iron nutrients were provided by organic matter with all soil horizons. Forty years of organic matter application increase soil contents of iron in top soils of Kuwait more than seventeen folds.the high contents of calcareous materials provide good storage capacities for iron and decrease iron toxicity s in high contents of organic matter application. Although with long duration of organic matter application in Kuwait indicate high content of micronutrients elements, but the availability s comparatively to plants' roots are low mostly due to high content of calcareous materials. Manganese contents increase enormously in all soils profile with the application of organic matter. Top soils with forty years application of organic matter contain more than twenty folds of manganese element. The high accumulation of manganese can be noticed in all soil profiles. Zinc accumulations even were exceeded both the iron and manganese content in all soils with added organic matter. Over thirty folds dilatation were recognized of zinc contents with all soils horizons. Boron element content also increased but not as other micro nutrients within the soils profile. This may be due to calcareous fixation of this element by calcareous materials in Kuwait soils, since the calcium and sodium borate s are reasonably soluble (Bowman and Halvorson, 1998). Copper contents increase in all soils profile as the iron, zinc and manganese. Correlation of organic matters application to the coarse texture of Kuwait reveal high release of micronutriens in the soil solution and undoubtedly an important fertility factor. 1507-3

Table 2 Effect of organic matter application on Kuwait soils total content of micronutrients. Duration Soil Depth Years cm Fe Mn Zn B Cu 0 0-2 2.465 g L -1 0.927 g L -1 0.638 g L -1 0.200 g L -1 0.233 mg L -1 20 0-2 7.012 g L -1 6.798 g L -1 3.434 g L -1 0.387 g L -1 0.520 mg L -1 40 0-2 42.948 g L -1 20.588 g L -1 20.525 g L -1 7.077 g L -1 17.094 mg L -1 0 0-5 2.738 mg L -1 0.977 mg L -1 0.098 mg L -1 0.031 mg L -1 0.173 mg L -1 20 0-5 3.921 mg L -1 4.040 mg L -1 2.971 mg L -1 0.408 mg L -1 0.469 mg L -1 40 0-5 36.881 mg L -1 14.857 mg L -1 17.215 g L -1 5.698 mg L -1 5.038 mg L -1 0 5-10 2.065 mg L -1 0.904 mg L -1 0.312 mg L -1 BD 0.243 mg L -1 20 5-10 11.605 mg L -1 4.081 mg L -1 1.700 mg L -1 0.609 mg L -1 0.494 mg L -1 40 5-10 43.843 mg L -1 15.250 mg L -1 21.898 mg L -1 1.085 mg L -1 4.237 mg L -1 0 10-15 2.615 mg L -1 0.614 mg L -1 0.187 mg L -1 BD 0.358 mg L -1 20 10-15 28.979 mg L -1 4.102 mg L -1 1.206 mg L -1 0.542 mg L -1 0.422 mg L -1 40 10-15 42.753 mg L -1 14.273 mg L -1 18.835 mg L -1 0.582 mg L -1 4.237 mg L -1 Calcium contents significantly decrease in forty years application of organic matter compare to other treatments (Table 3). At the same time calcium contents within the forty years treatment have increased through the soils lower horizons and decreased in the other treatments. Continuous water irrigation and organic matter reactions within the soils increase calcium cations solubility. Calcium concentration with constant farming moved to the lower soils profiles. Magnesium concentration in the soils solution increased in all soils profiles with the application of organic matters. Potassium, phosphorus and sulfur all highly increased in all soils horizons with continuous application of organic matters. Application of organic matters in different soils of Kuwait improve nutrients contents of the soils. Table 3 Effect of organic matter application on Kuwait soils total contents of macronutrients. Duration Soil Depth Ca Mg K P S (Years) (cm) (mg L -1 ) 0 0-2 190.416 014.151 013.130 004.776 051.267 20 0-2 188.333 091.462 0158.52 049.110 466.150 40 0-2 104.320 074.205 2252.10 012.876 1029.30 0 0-5 188.424 008.693 014.820 004.585 005.642 20 0-5 185.844 022.731 063.270 009.162 2533.60 40 0-5 126.140 390.553 4257.80 018.457 1052.5O 0 5-10 186.839 009.989 015.710 004.449 001.761 20 5-10 177.254 038.971 080.280 009.339 1000.40 40 5-10 172.619 065.521 335.480 070.476 135.880 0 10-15 180.779 010.031 013.770 004.329 001.195 20 10-15 153.411 041.184 081.880 009.007 749.980 40 10-15 146.685 053.412 334.690 066.902 138.770 1507-4

Table 4 Effects of organic matter on macro-nutrients contents. Duration (Years) Macro-Nutrients Contents Ca Mg K P S (mg L -1 ) 0 190.416 014.151 013.130 04.776 051.267 20 188.333 091.462 158.520 49.110 466.150 40 104.320 074.205 223.271 12.876 180.213 Conclusion and Remark Soil of Kuwait is poor with organic matter and plant nutrients and need heavy application of fertilizer and organic materials to improve soils productivity. Organic materials are available in large quantities in Kuwait from animal and municipal wastes. Research findings in three soils treated with organic waste materials with various time duration indicate extreme changes in the soils physical and chemical properties. Soils bulk densities decrease and soil water holding capacities increase. With limited irrigation water resources in Kuwait these two important factors will have large impact in irrigation water saving. Macro and micro nutrients contents increase within the soil solution except calcium in the top soils. Organic materials will improve soil productivity in Kuwait and plant growth and development. Research activities should concentrate mainly on nutrients interaction within the soil solution in Kuwait. High concentration of macro and micro nutrients were achieved from organic matter application to various soils in Kuwait. Interaction of these added nutrients with soil contents of calcareous materials can be studied more intensively to understand nutrients availability to plants. Nutrients interaction and stability within the soil solution can be investigated more scientifically to improve nutrients availability. References Abdal, M. and Al-Qallaf. 1993. Water management for the greenery of Kuwait. Acta Horticulturae, Irrigation of Horticultural Crop. 335:95-100. Abdel Rahman, H.A., M.H. Dahab and M.A. Mustafa. 1996. Impact of soil amendments on intermittent evaporation, moisture distribution and salt redistribution in salinesodic clay soil columns. Soil Science. 161(11)793-802. Bowman, R.A. and A.D. Halvorson. 1998. Soil chemical changes after nine years of differential N fertilization in a No-till dryland wheat-corn-fallow rotation. Soil Science 163(3)241-247. Dierolf, T.S., L.M. Arya and R.S. Yost. 1997. Water and cation movement in an Indonesian Ultisol. Agronomy Journal 89(4):572-578. Kamau, P.A., T.R. Ellsworth, C.W. Boast and F.W. Simmons. 1996. Tillage and cropping effects on preferential flow and solute transport. Soil Science 161(9):549-561. Larney, F.J. and H.H. Janzen. 1996. Restoration of productivity to desurfaced soil with livestock manure, crop residue and fertilizer amendments. Agronomy Journal 88 (6):921-927. 1507-5