ACTA PEDOLOGICA SINICA Nov.,2007 ,,, [4,5] [6], [1,2 ] 50 % 60 %, [3 ] g,e2mail ac. cn

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1 44 6 Vol144,No ACTA PEDOLOGICA SINICA Nov., g (, ),, : ;, ;, ;, ;, ;,,,, ; 3 ;, ; ; S15217 A,,,,, 1113 hm 2, [1,2 ],,, 90 %, 60 % 80 % 50 % 60 %, [3 ],,,,,, [4,5],, [6],,,, [7], [8,9],,,, 1 111,, 2 mm,, % % %, 1163 %( 3 (kzcx22yw240623) (2005CB121108) (863 ) (2006AA100207) (200401) g,e2mail ac. cn : (1970 ),, E2mail ac. cn : ; :

2 6 : 1017 ) %, 8103 %,2 h,215 h g kg - 1,pH , 45 cm 15 cm 55 cm, 1 15 cm cm, cm 9, 1 Fig1 1 Schematic plan of the apparatus in the simulation experiment cm, 412 g kg - 1,, 1155 g cm - 3 (5 cm), 50 cm 9, 110 L h L h L h - 1,,,, (abcd ),,,,, L h - 1, 015 cm 4 h, 112 cm, ml 16 cm,, 9 :00 6 : L h - 1,4 h, ml, 0125 L h - 1, ml, 2 2,,, 0125 L h - 1,,,,, 110 L h L h - 1,,,,, (0125 L h - 1 ),,,,,,,,,,,,, 2a,,,,,, cm d - 1, 014 L h - 1, (750 m 3 hm - 2 ), 30 cm, (, 30 cm 60 cm 30 cm),,, 212,, 1

3 Fig1 2 Movement of wetted front in treatments different in emitter discharge rate 1 Table 1 Changes in water suction of the solum with time of water infiltration ( kpa) Emitter discharge rate Time Number of tensiometer (L h - 1 ) (h)

4 6 : 1019,,,,,, ;,, 110 L h L h - 1,,,, 0125 L h - 1, 122, 80 kpa,,,, 213 3,110 L h - 1,, ( 5 cm) EC ds m - 1,,,20 h 7118 ds m - 1,,,,44 h EC ds m - 1,,,,, 015 L h - 1,, EC ds m - 1, 32 h 7180 ds m - 1,,,3 d (0125 L h - 1 ),, ,122,,,, 3 d,,015 L h L h - 1,, 3 Fig1 3 Salt leaching in treatments different in emitter discharge rate

5 ( ),, (abcd ),,,, [10,11 ],,, 1/ 4, r, d,, : v = 1 4 r2 d (1), 15 % [12 ], : w = ( ) v ( m - 0 ) (2), w ; v ; m ; 0,,, 3 1),, 1/ 2, L h - 1 2),,, 3 d 3), 4), : w = ( ) v ( m - 0 ) [ 1 ],,.., 2006,25 (1) : Wang S L, Gao Z Y, Guo T T. Application of MODFLOW model in the study of soil salinization development and controlling measures ( In Chinese ). Journal of Irrigation and Drainage, 2006,25 (1) : [ 2 ],,,.., 2006,38 (2) : Luo T B, Ren W, Li Y, et al. Changes in soil salinity of saline soil irrigated with saline water in arid area ( In Chinese). Soils, 2006,38 (2) : [ 3 ] Dasberg S, Or D. Drip Irrigation. Berlin, Germany : Springer2Ver2 lag, [ 4 ],,,.., 2004, 23 (3) : Sun H Y, Li M S, Wang Z H, et al. Influence factors on soil wetting front under point drip irrigation( In Chinese). Journal of Irrigation and Drainage, 2004, 23 (3) :14 16 [ 5 ],,.., 2002,39 (6) : Lu D Q, Wang Q J, Wang W Y, et al. Factors affecting soil water movement and solute transport for film drip irrigation ( In Chinese). Acta Pedologica Sini2 ca, 2002, 39 (6) : [ 6 ],,.., 2004,41 (6) : Zhang Z H, Cai H J, Yang R Y. An empirical solution of characteristic values of wetted solum under surface drip irrigation ( In Chinese). Acta Pedologica Sinica, 2004,41 (6) : [ 7 ],,.., 2003,17 (1) : 1 4. Li Y, Wang W Y, Wang Q J, et al. Experimental study on water and salt transport characteristics under infiltration of non2sufficient trickle irrigation ( In Chinese). Journal of Soil and Water Conservation, 2003,17(1) : 1 4 [ 8 ] Zhou J B, Xi J G, Chen Z J, et al. Leaching and transformation of nitrogen fertilizers in soil after application of N with irrigation. Pedo2 sphere, 2006,16 (2) : [ 9 ],.., 2003,11 (3) : Hu X T, Li M S. Effect of trickle irrigation under sub2film on the soil conditions of rhi2 zosphere in cotton ( In Chinese). Chinese Journal of Eco2Agriculture, 2003,11 (3) : [10 ].., 2004,26 (1) : Liu S J. Test and study on characteristics of wetted body of bilateral interference infiltration of film hole ( In Chi2 nese). Ground Water, 2004,26 (1) : [11 ],,. -., 2001,20 (2) : Li Y, Wang W Y, Wang Q J. A breakthrough thought for water saving and salinity control in arid and semi2arid area Under2film trickle irriga2 tion (In Chinese). Irrigation and Drainage, 2001,20(2) : [12 ] FAO. Drainage Design Factors. Irrigation and Drainage Paper No. 38. Rome,

6 6 : 1021 MOVEMENT AND REDISTRIBUTION OF WATER AND SAL T IN RELATION TO EMITTER DISCHARGE RATE Liu Chunqing Yang Jinsong g Chen Xiaobing Chen Deming ( Institute of Soil Science, Chinese Academy of Sciences, Nanjing , China) Abstract A study on movement and redistribution of water and salt in soil in relation to emitter discharge rate was con2 ducted through indoor simulation tests in soil columns1 Results show that depending on emitter discharge rate, the wetted front at the meeting interface of waters from two emitters appeared to be either elliptical or circular1 High emitter discharge rates acceler2 ated horizontal movement of the water, resulting in greater horizontal dispersion rate than vertical infiltration rate1 With decreased emitter discharge rate, the distance of horizontal infiltration approached to that of vertical infiltration1 Wetted soil volume was re2 lated to total quantity of the irrigation water rather than emitter discharge rate1 Based on the rules of wetted front movement, a proper emitter discharge rate was suggested for field practice1 At the end of drip irrigation, water and salt had experienced impor2 tant redistribution processes1 The movement of water and salt to deeper soil layers promoted desalination of the upper soil layer1 The effect was markedly better with low emitter discharge rates than high emitter discharge rates1 The movement of salt was the most active onthe first three days of redistribution1 A proper water volume per emitter that satisfies both the demand of a crop for growth and the need of the soil for salt leaching was worked out through the experiment, whichis sure of certain practical signifi2 cance. Key words Drip irrigation ; Soil water and salt movement ; Redistribution