1、 19 null 3 null l null u null null null null null Vo.l 19null No. 32005 M 5 Journal o fA rid Land Resources and Env ironm ent M ay. 2005 c I | : 1003- 7578 ( 2005 ) 03- 137- 04 Z v Y | H W 0 r Y * 1, f 1, f 1, 1, 2( 1. 9 F B r g 9 F ,r A , 5 d # 9 , y 7 r c 9 bm 1r v 8 H W 0 M F ig. 1 The change o f
2、 am ount o f so ilaggrega te in diffe rent aged forests7 r / T z M Q , “ - 9 F ,/ r c 9 h , . C b ? r 1 , | 20a X ? , / r c A h , / 20a r _ 5mm )138 null l null u null null null null null 19 9 A 4 , “ H W 0 y 9 F t , 10aa20a s Y 1 v (| B M )9 F 12.68% 17. 00%, 7 v 8 9 A 4 , s Y 9 F 7. 64% 4. 97%b V
3、/ # Z , P r V Y v 4 ,r v d # 9 F , Y i 9 , = r _ 9 ( j _ r ) bV 3 r v 8 c 9 ( A ) H W 0 M T ab le. 3 T he change of amoun t increm ent o f so il agg rega te in d iffe rent aged fo restsr ( cm )D 1 (% ) D2 (% ) D3 (% ) 5mm5 2mm2 1mm1 0. 25mm5mm5 2mm2 1mm1 0. 25mm5mm5 2mm2 1mm1 0. 25mm5mm )av 8 ( 5 2m
4、m )av 8 ( 2 1mm )a 8 ( 1 0. 25mm ) 8 ( 5mmv v 8 ( 9 F 6. 25% , r V V Y i ( v , A U r d ! s ? ; 25mmv 8 2 1mmv 8 V V 9 F 9 d A , ( 4 3. 61% 5. 93% , ! “ s = r x X v ; 7 0. 025mm v 8 5 A h l ,h l ( r 18. 04%, V n , | H W , v 8 h , h q / t , 4A ,/ 15a 10aM 1 , v 8 / 5. 38% ,7 20a 15aM 1 / 2. 02%, 20a (
5、 Z )M 1 + , / 20a , r 3 ? b2. 3. 2 土壤颗粒组成 Y r R F y 0 , # % T b Z v Y r 1 ( r ),s R F r ? 3 V # r V E s 1 b $ r F Y . v , V Y r r V , . Y r M V , 7 Y r R F s r Q W M br R v l , R W T Y ,B ( 1 0. 05mm ) 3 , M W s ; x ( 0. 05 0. 01)V C ,M W V ; T ( 0.001mm ) Q 3 T r , ,M W bV 4 r F s c 9 H W 0 M T ab.
6、 4 The so il tex ture w ith different tim e g rader ( cm )D5a D15a D 20a1 0. 05mm0. 05 0. 01mm 0. 001mm1 0. 05mm0. 05 0. 01mm 0. 001mm1 0. 05mm0. 05 0. 01mm 0. 001mm0 20 - 19. 17 17. 43 3. 85 - 9. 97 15. 76 1. 62 - 19. 63 4. 51 12. 2620 40 - 29. 56 5. 03 18. 79 - 23. 67 6. 54 21. 17 - 30. 04 - 2. 3
7、23. 5940 60 - 28. 27 1. 00 12. 98 - 26. 90 3. 22 11. 01 - 22. 30 - 6. 78 13. 7660 80 - 4. 01 - 4. 63 - 1. 46 - 20. 83 0. 30 3. 39 - 17. 29 - 8. 68 8. 28 ( - 20. 25 4. 71 8. 54 - 20. 34 6. 46 9. 30 - 22. 32 - 3. 31 14. 47 V 4 V , | r R F M v , v B M | M 1 , Q # ( c 9 A h ,i H W 0 9 F 7 h t , V | 10a
8、- 20. 25%h 20a - 22. 32%, 7 T c 5 z M Q , H W 0 9 F 7 T c A 9 F , 8. 54%9 F 14.47%, O r g r M T r , 7 A 9 v r 9 d # , P 5 d # d 5 d # 1 139 3 null Z v Y | H W 0 r Y? 3 v M ,9 r + ? 4 bV V 4 V A , | H W 9 F r ? 3 Q R F s c M l ,| 10ar T c 1 v 9 F 12. 98 18. 79%,15a9 11. 01 21. 17%,7 20a 5 4 13. 76 23
9、. 59%, r + A , r C r T C , 7 T g ! “ 1 s , V n , “ l !s s H q g ? 3 A M , H W ,r T 9 F ,r 9 d # 9 v , 7 v 4 r g ? b3 ( 1) | r Y v , M r _ # r V , 7 M r # R M V , P H W = ? 3 _ r bnull null ( 2) “ H W 0 M ,V r A M l , 7 / 5 9 v t , M r T V M 1 bnull null ( 3) r V V / r c 9 H W 0 A 9 F ,r A , 9 d # 9v
10、 , 5 d # d 5 d # 1 9 F ;r R F ? 3 A M ,i c h ,T c l 9 F t b I D 1f , by S . b $ r Y J. 2002: 10( 1) 74- 78. 2 1 , m . r + 1 r J. r 2000: 14 ( 4) 99 - 103. 3I ! .r M r s J. j v 2000: 23 ( 1 ) 12- 17. 4f t . j r ? # r 1 “ J. l u j 1994: ( 6) 32 37. 5 V l . r d # A J J. S S ( B ), 1987: ( 1 ) 1309- 131
11、6. 6 , . r u r + J. C r S 1994: 121 124. 7f , _ . r Z E J. : S 1986: 17 55. 8 , i . r bW s J. 3 2000: 20( 6 ) 946- 950.Effects ofDifferentTimeGradientofCroppingLandConversion toForest on SoilPhysicalProperties inDaTongCounty ofQingHaiL IW en- zhong, ZHANG W ei- hua, ZHANG H ao,ZHOU X in- cheng, WANG
12、 X iu- rong( College of Soil andW ater Con servation, BFU, Key Laboratory of Soil and W ater Conservation andD esertification Com bating of the M in istry of Education, 100083, Be ijing)Abstractnull null The research m ainly investigated the variation and im provem ent of so il physica l properties
13、under d iffernullent tim e gradient of cropping land to fores.t The results show ed that there had a huge in fluence on so il physicalproperties a fter converting cropp ing land to fores,t and m ade it evo lve d irective ly to forest so il in short tim e. W iththe continuance of the tim e, soil structure w as im proved obv iously, total porosity increased, and its ability o fw anullter retention, nutrient supplem ent and anti- erosion w as im proved.null null Keywords: tim e grad ien;t physica l properties; directive evolution140 null l null u null null null null null 19
