Runoff and Erosion as Affected by Soil Spatial Variation and Temporal Conditions

Öz

Soil loss by overland flow in agricultural lands or watersheds is a severe problem worldwide. Agricultural

fields usually exhibit a complex spatio-temporal variability related to soil characteristics, and hence variable sources of

sediment and pollutant, and hydrologically sensitive areas. We have studied and quantified, in a systematic manner, the

contribution of soil spatial variation/properties and temporal conditions on runoff and soil erosion from numerous soils.

The soil properties and conditions included: (1) soil texture classes and other properties; (2) predominant clay mineralogy

(kaolinitic, illitic and smectitic); (3) organic matter content; (4) antecedent moisture contents (from dry to full saturation);

(5) rain kinetic energy (KE, 0-22 kJ/m3); (6) wetting rates of soil by rainfal or irrigation water; (7) tillage type (conventional

and minimum tillage); (8) water quality (rain, fresh, effluent or saline irrigation water); (9) use of soil amendments

(polymer, gypsum and manure).

Runoff and erosion were highly affected by clay mineralogy, and increased exponentially with the increase in rain KE,

rate of soil wetting and soil sodicity. Rain KE and water quality played a predominate role in determining infiltration, runoff

and soil loss in medium- and coarse-textured soils, and wetting condition played a predominate role in fine-textured

soils. Soils from semi-arid regions, having moisture content in the range between wilting point and field capacity were

less susceptible to runoff and soil loss. Effects of minimum-tillage depend on soil texture and irrigation water quality. However,

effects of minimum-tillage were lower than conventional one. Application of a small amount of polymer in combination

with gypsum may effectively decrease runoff and soil loss by 2-4 times relative to the control.

The presented data on runoff and soil erosion may significantly assist in improving our understanding and modelling of

the changes in the degree of runoff and erosion in arid and humid zone soils.

Anahtar Kelimeler

• Runoff,erosion,spatial variation,intrinsic properties and temporal condition

Toprak Mekansal Varyasyonu ve Zamansal Koşullarla Etkilenmiş Yüzey Akış ve Erozyon

Öz

Tarım arazileri veya su havzalarında toprağın yüzey akış ile kaybı tüm dünyada ciddi bir sorundur. Tarım alanları, genellikle, toprak özellikleri, değişen sediment yükü, kirleticiler ve hidrolojik hassas alanlar nedeniyle karmaşık bir uzaysal-zamansal değişkenlik gösterebilir. Bu çalışmada, toprağın mekansal değişimi/özelliklerinin ve zamansal koşulların yüzey akış ve toprak erozyonuna etkisi, çok sayıdaki toprak örnekleri üzerinde sistematik bir şekilde araştırılarak değerlendirilmiştir. Değerlendirmede kullanılan toprak özellikleri ve koşulları şunlardır: (1) toprak yapısı sınıfları ve diğer özellikleri; (2) baskın kil mineraloji (kaolinitik illitic ve smectitic), (3) organik madde içeriği, (4) nem içerikleri (kurudan tam doygunluğa kadar); (5) yağmur kinetik enerjisi (KE, 0-22 kJ m-3); (6) yağmur veya sulama suyu ile toprak ıslanma oranları; (7) tarım şekli (konvansiyonel ve minimum toprak işleme), (8) su kalitesi (yağmur, taze, atık veya tuzlu sulama suyu); (9) toprak düzenleyicilerin kullanımı (polimer, jips ve gübre).Yüzey akış ve erozyon kil mineralojisinden oldukça etkilenmekte; yağışın KE, toprak ıslanma oranı ve toprak tuzluluğu katlanarak artmaktadır. Yağışın KE ve su kalitesi, orta ve kaba bünyeli topraklarda, ıslanma koşulları ise kil dokulu topraklarda infiltrasyon, yüzeysel akış ve toprak kaybının belirlenmesinde, baskın bir rol oynamaktadır. Solma noktası ile tarla kapasitesi arasında nem içeriğine sahip yarı-kurak bölgelerdeki toprakların yüzey akış ve toprak kaybına daha az duyarlı olduğu görülmüştür. Minimum toprak işleme etkileri, toprak yapısı ve sulama suyu kalitesine bağımlıdır. Ancak, minimum toprak işlemenin etkileri geleneksele göre daha düşük bulunmuştur. Küçük miktarda polimerin jips ile kombinasyonu, kontrol denemelerine göre, yüzey akış ve toprak kaybını etkili bir şekilde 2-4 kat azaltabilmektedir. Yüzey akış ve toprak erozyonu üzerine sunulan veriler kurak ve nemli bölge topraklarının yüzey akış ve erozyon derecelerinin modellenmesi ve anlaşılmasında önemli ölçüde yardımcı olabilir

Anahtar Kelimeler

• Yüzey akış, erozyon, mekansal değişimi, içsel özellikleri ve zamansal durumu

Kaynakça

1. Agassi M, Shainberg, I., Morin, J., 1981. Effect of electrolyte con- centration and soil sodicity on infiltration rate and crust forma- tion. Soil Science Society of American Journal, 48: 848–851.
2. Hudson, N., 1971. Soil conservation. Cornell University Press. It- haca, NY, USA 320 p.
3. Lado, M., Ben-Hur, M., 2004. Soil mineralogy effects on seal for- mation, runoff and soil loss. Applied Clay Science, 248:209– 224.
4. Levy, G. J., Levin, J., Shainberg, I., 1994. Seal formation and in- terrill soil erosion. Soil Science Society of American Journal, 58:203–209.
5. Levy, G.J., Levin, J., Shainberg, I., 1997. Prewetting rate and aging effects on seal formation and interrill soil erosion. Soil Scien- ce, 162: 131-139.
6. Levy, G.J., 1995. Soil stabilizers. In: Agassi, M. (ed), Soil erosi- on and rehabilitation, Marcel Dekker NY, USA, pp.267-299.
7. Mandal, U.K., Bhardwaj, A.K., Warrington, D.N., Goldstein, D., Bar Tal, A., Levy, G.J., 2008. Changes in soil hydraulic con- ductivity, runoff, and soil loss due to irrigation with different types of saline-sodic water. Geoderma, 144: 509-516.
8. Mamedov, A.I., Shainberg, I., Levy, G.J., 2000. Rainfall energy ef- fects on runoff and interrill erosion in effluent irrigated so- ils. Soil Science, 165: 535-544.

9. Mamedov, A.I., Shainberg, I., Levy, G.J., 2001. Irrigation with eff- luents: effects of prewetting rate and clay content on runoff and soil loss. Journal of Environmental Quality, 30: 2149- 2156.
10. Mamedov, A.I., Shainberg, I., Levy, G.J., 2002. Wetting rate and so- dicity effects on interrill erosion from semi arid Israeli soils. Soil and Tillage Research, 68: 121-132.
11. Mamedov, A.I., Huang,C., Levy, G.J., 2006. Antecedent moisture content and aging duration effects on seal formation and ero- sion in smectitic soils. Soil Science Society of American Jo- urnal, 70: 832-843.
12. Mamedov, A.I., Shainberg, I., Wagner, L.E., Warrington, D.N., Levy, G.J., 2009. Infiltration and erosion in soils treated with dry PAM, of two molecular weights, and phosphogypsum. Australian Journal Soil Research, 47: 788-795.
13. Mamedov, A.I., Wagner, L.E., Huang, C., Norton, L.D., Levy, G.J., 2010. Polyacrylamide effects on aggregate and structure stabi- lity of soils with different clay mineralogy. Soil Science Soci- ety of American Journal, 74: 1720-1732.
14. Norton, L.D., Mamedov, A.I., Huang, C., Levy, G.J., 2006. Soil aggregate stability as affected by long-term tillage and clay type. Advances in GeoEcology 38: 422-429
15. Qui, Z., Walter, M.T., Hall, C., 2007. Managing variable source pol- lution in agricultural watersheds. Journal of Soil and Water Conservation, 63: 115-122.
16. Reichert, J.M., Norton, L.D., Favaretto, N., Huang, C., Blume, E., 2009. Settling velocity, aggregate stability, and interrill erodi- bility of soils varying in clay mineralogy. Soil Science Society of American Journal, 73:1369–1377.
17. Shainberg, I., Goldstein, D., Levy, G.J., 1996. Rill erosion depen- dence on soil water content, aging and temperature. Soil Sci- ence Society of American Journal, 60: 916-922.
18. Shainberg, I., Mamedov, A.I., Levy, G.J., 2003a. The role of wetting rate and rain energy in seal formation and interrill erosion. Soil Science, 168: 54-62.
19. Shainberg, I., Mamedov, A.I., Ben-Hur, M., 2003b. Minimizing desertification by using appropriate soil tillage. In: NATO - CCMS and Science Committee Workshop on Desertification in the Mediterranean Region, Valencia, Spain, p.99.
20. Sharpley, A.N., Daniel, T., Gibson, G., Bundy, L., Cabrera, M., Sims, Lemunyon, J., Kleinman, P.J., Parry, R., 2006. Best ma- nagement practices to minimize agricultural phosphorus im- pacts on water quality. Agricultural Research Service Publi- cation. 52 p.
21. Stern, R., Ben-Hur, M., Shainberg, I., 1991. Clay mineralogy effect on rain infiltration, seal formation and soil losses. Soil Scien- ce. 152, 455-462.
22. Walter, M.T., Walter, M.F., Brooks, E.S., Steenhuis, T.S., Boll, J., Weiler, K.R., 2000. Hydrologically sensitive areas: variable source area hydrology implications for water quality risk as- sessment. Journal of Soil and Water Conservation, 3: 277-284.
23. Warrington, D.N., Mamedov, A.I., Bhardwaj, A.K., Levy, G..J., 2009. Primary particle size distribution of eroded material af- fected by degree of aggregate slaking and seal development. European Journal of Soil Science, 60: 84-93.
24. Yu, J., Lei, T., Shainberg, I., Mamedov, A.I., Levy, G.J., 2003. Infilt- ration and erosion in soils treated with dry PAM and gypsum. Soil Science Society of American Journal, 67: 630-636.