Agricultural water conservation - A global perspective

Journal of Crop Production

Volumn 2, Issue 2, 1999, Pages 1-36

  Unger, Paul W ^a   Howell, Terry A ^a  

^a Conserv and Prod Res Laboratory ^*  (United States)

Author keywords

Dryland agriculture; Evaporation; Irrigated agriculture; Irrigation methods; Irrigation water management; Water infiltration; Water retention; Weed control

Indexed keywords

EID: 0033389356     PISSN: 1092678X     EISSN: None     Source Type: Journal    
DOI: 10.1300/J144v02n02_01     Document Type: Review

References (137)

1. Abdullah, S.M., R. Horton, and D. Kirkham. (1985). Soil water evaporation suppression by sand mulches. Soil Science 139: 357-361.
2. Abbot, J.S. (1984). Micro irrigation - World wide usage. ICID Bulletin 33: 4-9.
3. Abu-Awwad, A.M. and M.R. Shatanawi. (1997). Water harvesting and infiltration in arid areas affected by surface crust: Examples from Jordan. Journal of Arid Environments 37: 443-452.
4. Agassi, M., I. Shainberg, D. Warrington, and M. Ben-Hur. (1989). Runoff and erosion control in potato fields. Soil Science 148: 149-154.
5. Alegre, J.C. and M.R. Rao. (1996). Soil and water conservation by contour hedging in the humid tropics of Peru. Agriculture, Ecosystems & Environment 57: 17-25.
6. Amir, J. and T.R. Sinclair. (1996). A straw mulch system to allow continuous wheat production in an arid climate. Field Crops Research 47: 21-31.
7. Beach, T. and N.P. Dunning. (1995). Ancient Maya terracing and modern conservation in the Petén rain forest of Guatemala. Journal of Soil and Water Conservation 50: 138-145.
8. Benyamini, Y. and P.W. Unger. (1984). Crust development under simulated rainfall on four soils. Agronomy Abstracts, pp. 243-244.
9. Bertrand, A.R. (1966). Water conservation through improved practices. In Plant Environment and Efficient Water Use, eds. W.H. Pierre, D. Kirkham, and R. Shaw. Madison, WI: American Society of Agronomy, pp. 207-235.
10. Bishop, A.A., W.R. Walker, N.L. Allen, and G.J. Poole. (1981). Furrow advance rates under surge flow systems. Journal of Irrigation and Drainage Division (ASCE) 107(IR3): 257-264.
11. Black, A.L. (1986). Resources and problems in the northern Great Plains area. In Planning and Management of Water Conservation Systems in the Great Plains States, Proceedings of a Workshop, Lincoln, NE, October 1985. Lincoln, NE: U.S. Department of Agriculture, Soil Conservation Service, Midwest National Technical Center, pp. 25-38.
12. Black, A.L. and J.K. Aase. (1988). The use of perennial herbaceous barriers for water conservation and the protection of soils and crops. Agriculture, Ecosystems and Environment 22/23: 135-148.
13. Black, A.L. and A. Bauer. (1986). Soil water conservation strategies for Northern Great Plains. In Planning and Management of Water Conservation Systems in the Great Plains States. Proceedings of a Workshop, Lincoln, NE, October 1985. Lincoln, NE: U.S. Department of Agriculture, Soil Conservation Service, Midwest National Technical Center, pp. 76-86.
14. Black, A.L. and F.H. Siddoway. (1976). Dryland cropping sequences within a tall wheatgrass barrier system. Journal of Soil and Water Conservation 31: 101-105.
15. Black, A.L. and D.L. Tanaka. (1996). A conservation tillage-cropping systems study in the northern Great Plains of the USA. In Soil Organic Matter in Temperate Agroecosystems, eds. E.A. Paul, K.A. Paustian, E.T. Elliott, and C.V. Cole. Boca Raton, FL: Lewis Publishers, pp. 335-342.
16. Brady, N.C. (1988). Scientific and technical challenges in dryland agriculture. In Challenges in Dryland Agriculture - A Global Perspective, eds. P.W. Unger, T. V. Sneed, W.R. Jordan, and R. Jensen. College Station, TX: Texas Agricultural Experiment Station, pp. 6-12.
17. Brown, P.L., A.D. Halvorson, F.H. Siddoway, H.F. Mayland, and M.R. Miller. (1982). Saline-seep diagnosis, control, and reclamation. U.S. Department of Agriculture Conservation Research Report No. 30. Washington, DC: U.S. Government Printing Office.
18. Burt, C.M., A.J. Clemmens, T.S. Strelkoff, K.H. Solomon, R.D. Bliesner, L.A. Hardy, T.A. Howell, and D.E. Eisenhauer (1997). Irrigation performance measures: Efficiency and uniformity. Journal of Irrigation and Drainage Engineering 123: 423-442.
19. Camp, C.R. (1998). Subsurface drip irrigation: A review. Transactions of the ASAE 41: 1353-1367.
20. Campbell, C.A., B.C. McConkey, V.O. Biederbeck, R.P. Zentner, D. Curtin, and M.R. Peru. (1998). Long-term effects of tillage and fallow-frequency on soil quality attributes in a clay soil in semiarid southwestern Saskatchewan. Soil & Tillage Research 46: 135-144.
21. Campbell, C.A., B.G. McConkey, R.P. Zentner, F. Selles, and F.B. Dyck. (1992). Benefits of wheat stubble strips for conserving snow in southwestern Saskatchewan. Journal of Soil and Water Conservation 47: 112-115.
22. Cannell, G.H. and H. E. Dregne. (1983). Regional setting. In Dryland Agriculture, Monograph 23, eds. H.E. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 3-17.
23. Carroll, C., H. Halpin, P. Burger, K. Bell, M.M. Sallaway, and D.F. Yule. (1997). The effect of crop type, crop rotation, and tillage practice on runoff and soil loss on a Vertisol in central Queensland. Australian Journal of Soil Research 35: 925-938.
24. Chitale, M.A. (1987). Water management in drought prone areas. Water Supply 5:11-130. Oxford.
25. Choudhary, M.I., A.A. Shalaby, and A.M. Al-Omran. (1995). Water holding capacity and evaporation of calcareous soils as affected by four synthetic polymers. Communications in Soil Science and Plant Analysis 26(13&14): 2205-2215.
26. Clothier, B.E. (1989). Research imperatives for irrigation science. Journal of Irrigation and Drainage Engineering (ASCE) 115: 421-448.
27. Clothier, B.E. and S.R. Green. (1994). Rootzone processes and the efficient use of irrigation water. Agricultural Water Management 25: 1-12.
28. Cogle, A.L., M. Littleboy, K.P.C. Rao, G.D. Smith, and D.F. Yule. (1996). Soil management and production of Alfisols in the semi-arid tropics: III. Long-term effects on water conservation and production. Australian Journal of Soil Research 34: 103-111.
29. Critchley, W.R.S., C. Reij, and T.J. Wiltcocks. (1994). Indigenous soil and water conservation: A review of the state of knowledge and prospects for building on traditions. Land Degradation & Rehabilitation 5: 293-314.
30. Cutforth, H.W. and B.C. McConkey. (1997). Stubble height effects on microclimate, yield and water use efficiency of spring wheat grown in a semiarid climate on the Canadian prairies. Canadian Journal of Plant Science 77: 359-366.
31. de Jong, E. and H. Steppuhn. (1983). Water conservation: Canadian Prairies, In Dryland Agriculture, ed. H.H. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America. Inc., and Soil Science Society of America, Inc., pp. 89-104.
32. Dedrick, A.R., L.J. Erie, and A.J. Clemmens. (1982). Level-basin irrigation. In Advances in Irrigation, Volume 1. ed, D. Hillel. New York, NY: Academic Press, Inc., pp. 105-145.
33. Eck, H.V. and H.M. Taylor. (1969). Profile modification of a slowly permeable soil. Soil Science Society of America Proceedings 33: 779-783.
34. English. M.J., J.T. Musick, and V.V.N. Murty. (1990). Deficit irrigation. In Management of Farm Irrigation Systems, eds. G.J. Hoffman, T.A. Howell, and K.H. Solomon. St. Joseph, MI: American Society of Agricultural Engineers, pp. 631-663.
35. Fangmeier, D.D., W.F. Voltman, and S. Eftekharzadeh. (1990). Uniformity of LEPA irrigation systems with furrow drops. Transactions of the ASAE 33: 1907-1912.
36. FAO (Food and Agriculture Organization of the United Nations, Rome, Italy). (1998). World irrigated area. The FAOSTAT Database. FAOSTAT Agricultural Data. http://apps.fao.org/lim500/nph-wrap.pl?Irrigation&Domain=LUI&servlet=1
37. Frasier, G.W. and L.E. Myers. (1983). Handbook of Water Harvesting, Agriculture Handbook 600. Washington, DC: U.S. Department of Agriculture, Agricultural Research Service.
38. Gallacher, R.N. (1990). The search for low-input soil and water conservation techniques. In Topics in Applied Resource Management. Volume 2, Experiences with Available Conservation Technologies, eds. E. Baum, P. Wolff, and M.A. Zöbisch. Witzenhausen, Federal Republic of Germany: German Institute for Tropical and Subtropical Agriculture, pp. 11-37.
39. Gilley, J.R. and L.N. Mielke. (1980). Conserving energy with low-pressure center pivots. Journal of Irrigation and Drainage Division (ASCE) 106(IR1): 49-59.
40. Gilley, J.E., S.C. Finkner, R.G. Spomer, and L.N. Mielke. (1986). Runoff and erosion as affected by corn residues: Part I. Total losses. Transactions of the ASAE 29: 157-160.
41. Gleick, P.H. (1998). The world's water, 1998-1999. Washington, DC: Island Press.
42. Good, L.G. and D.E. Smika (1978). Chemical fallow for soil and water conservation in the Great Plains. Journal of Soil and Water Conservation 33: 89-90.
43. Greb, B.W. (1983). Water conservation: Central Great Plains, In Dryland Agriculture, ed. H.E. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 57-72.
44. Greb, B.W. (1979). Reducing drought effects on croplands in the west-central Great Plains. U.S. Department of Agriculture Bulletin No. 420. Washington, DC: U.S. Government Printing Office, 31 pp.
45. Harper, J. and O.H. Brensing. (1950). Deep plowing to improve sandy land. Bulletin B-362. Stillwater, OK: Oklahoma Agricultural Experiment Station.
46. Harrold, L.L. and W.M. Edwards. (1972). A severe test of no-till corn. Journal of Soil and Water Conservation 27: 30.
47. Hien, F.G., M. Rietkerk. and L. Stroosnijder. (1997). Soil variability and effectiveness of soil and water conservation in the Sahel. Arid Soil Research and Rehabilitation 11; 1-8.
48. Hill, R.W. and R.G. Allen. (1996). Simple irrigation scheduling calendars. Journal of Irrigation and Drainage Engineering (ASCE) 122: 107-111.
49. Hoffman, G.J., T.A. Howell, and K.H. Solomon (eds.). (1990). Management of Farm Irrigation Systems. St. Joseph, MI: American Society of Agricultural Engineers, 1040 p.
50. Howell, T.A., A. Yazar, A.D. Schneider, D.A. Dusek, and K.S. Copeland. (1995). Yield and water use efficiency of corn in response to LEPA irrigation. Transactions of the ASAE 38: 1737-1747.
51. Jacks, G.V., W.D. Brind, and R. Smith. (1955). Mulching. Commonwealth Bureaux of Soil Science (England) Technical Communication 49. Farnham Royal, Bucks., England: Commonwealth Agricultural Bureaux.
52. Jalota, S.K. (1993). Evaporation through a soil mulch in relation to mulch characteristics and evaporativity. Australian Journal of Soil Research 31: 131-136.
53. Jalota, S.K. and S.S. Prihar. (1990). Bare-soil evaporation in relation to tillage. Advances in Soil Science 12: 187-216.
54. Johnson, W.C. (1964). Some observations on the contribution of an inch of seeding time soil moisture to wheat yields in the Great Plains. Agronomy Journal 56: 29-35.
55. Jones, O.R. (1981). Land forming effects on dryland sorghum production in the southern Great Plains. Soil Science Society of America Journal 45: 606-611.
56. Jones, O.R. and R.N. Clark. (1987). Effects of furrow dikes on water conservation and dryland crop yields. Soil Science Society of America Journal 51: 1307-1314.
57. Jones, O.R. and V.L. Hauser. (1975). Runoff utilization for grain sorghum. pp. 277-283. In Proceedings Water Harvesting Symposium, ed. G. W. Frazier, February 1975. U.S. Department of Agriculture, ARS W-22.
58. Jones, O.R. and T.W. Popham. (1997). Cropping and tillage systems for dryland grain production in the Southern High Plains. Agronomy Journal 89: 222-232.
59. Kaushik, S.K. and R.C. Gautam. (1994). Response of rainfed pearl millet (Pennisetum glaucum) to water harvesting, moisture conservation and plant population in light soils. Indian Journal of Agricultural Sciences 64: 858-860.
60. Keen, M. (1991). Drip-trickle irrigation boosts Bedouin farmers yields. Ceres 130 23(4): 10-12.
61. Keller, J. and R.D. Bliesner. (1990). Sprinkle and trickle irrigation. New York, NY: Van Nostrand Reinhold.
62. Kemper, W.D., W.H. Heinemann, D.C. Kincaid, and R.V Worstell. (1981). Cablegation. I. Cable controlled plugs in perforated supply pipes for automated furrow irrigation. Transactions of the ASAE 24: 1526-1532.
63. Kemper, W.D., D.C. Kincaid, R.V. Worstell, W.H. Heinemann, T.J. Trout, and J.E. Chapman. (1985). Cabelgation systems for irrigation: Description, design, installation, and performance. U.S. Department of Agriculture. ARS Report 21.
64. Kemper, W.D., T.J. Trout, A.S. Humpherys, and M.S. Bullock. (1988). Mechanisms by which surge irrigation reduces furrow infiltration rates in a silty loam soil. Transactions of the ASAE 31: 821-829.
65. Krantz, B.A., J. Kampen, and S.M. Virmani. (1978). Soil and water conservation and utilization for increased food production in the semi-arid tropics. Hyderabad, A.P., India: International Crops Research Institute for the Semi-arid Tropics, 22 pp.
66. Kruse, E.G., D.A. Bucks, and R.D. von Bernuth, (1990). Comparison of irrigation systems. In Irrigation of Agricultural Crops. eds. B.A. Stewart and D.R. Nielsen. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America. Inc., pp. 475-508.
67. Laing, I.A.F. (1981). Evaluation of small catchment surface treatments. Australian Water Resources Council Technical Paper 61. Canberra, Aust.: Australian Government Publishing Service.
68. Lavake, D.E. and A.F. Wiese. (1979). Influence of weed growth and tillage interval during fallow on water storage, soil nitrates, and yield. Soil Science Society of America Journal 43: 565-569.
69. Lavee, H., J. Poesen, and A. Yair. (1997). Evidence of high efficiency water-harvesting by ancient farmers in the Negev Desert, Israel. Journal of Arid Environments 35: 341-348.
70. Lemon, E.R. (1956). The potentialities for decreasing soil moisture evaporation loss. Soil Science Society of America Proceedings 20: 120-125.
71. Lentz, R.D., I. Shainberg, R.E. Sojka, and D.L. Carter. (1992). Preventing irrigation furrow erosion with small applications of polymers. Soil Science Society of America Journal 56: 1926-1932.
72. Lyle, W.M. and J.P. Bordovsky. (1981). Low energy precision application (LEPA) irrigation system. Transaction of the ASAE 30: 1071-1074.
73. Lyle, W.M. and J.P. Bordovsky. (1983). LEPA irrigation system evaluation. Transactions of the ASAE 26: 776-781.
74. Martin, D.L., E.C. Stegman, and E. Fereres. (1990). Irrigation scheduling principles. In Management of Farm Irrigation Systems, eds, G.J. Hoffman, T.A. Howell, and K.H. Solomon. St. Joseph, MI: American Society of Agricultural Engineers, pp. 155-203.
75. McConkey, B.G., D.J. Ulrich, and F.B. Dyck. (1997). Slope position and subsoiling effects on soil water and spring wheat yield. Canadian Journal of Soil Science 77: 83-90.
76. Merriam, J.L. and J. Keller. (1978). Farm irrigation system evaluation: A guide for management. Logan, UT: Utah State University, Department of Agriculture and Irrigation Engineering, 271 p.
77. Miller, D.E. and J.S. Aarstad. (1972). Effect of deep plowing on the physical characteristics of Hezel soil. Circular 556. Pullman, Washington: Washington Agricultural Experiment Station.
78. Muchiri, G. and F.N. Gichuki. (1983). Conservation tillage in semi-arid areas of Kenya. In Soil and Water Conservation in Kenya, eds. D.B. Thomas and W.M. Senga. Nairobi, Kenya: University of Nairobi, Institute for Development Studies and Faculty of Agriculture, pp. 395-419.
79. Musick, J.T. and F.R. Lamm. (1990). Preplant irrigation in the Central and Southern High Plains - A review. Transactions of the ASAE 33: 1834-1842.
80. Musick, J.T, F.B. Pringle, and P.N. Johnson. (1983). Furrow compaction for controlling excessive irrigation water intake. St. Joseph, MI: American Society of Agricultural Engineers, Paper No. 83-2575.
81. Musick, J.T., F.B. Pringle, and J.D. Walker. (1987), Sprinkler and furrow irrigation trends-Texas High Plains. Applied Engineering in Agriculture 3: 190-195.
82. Musick, J.T., W.H. Sletten, and D.A. Dusek. (1971). Preseason irrigation of grain sorghum in the Southern High Plains. Transactions of the ASAE 14: 93-97.
83. Nakayama, F.S. and D.A. Bucks. (1986). Trickle Irrigation for Crop Production: Design, Operation, and Management. Amsterdam, The Netherlands: Elsevier Science Publishers B.V., 383 p.
84. Nielsen, D.C., R.M. Aiken, and G.S. McMaster, (1997). Optimum wheat stubble height to reduce erosion and evaporation. Conservation Tillage Fact Sheet #4-97. Published by: USDA-ARS, USDA-NRCS, and Colorado Conservation Tillage Association, 2 pp.
85. Norwood, C.A. (1992). Tillage and cropping system effects on winter wheat and grain sorghum. Journal of Production Agriculture 5: 120-126.
86. O'Leary, G.J. and Connor, D.J. (1997). Stubble retention and tillage in a semi-arid environment: 1. Soil water accumulation during fallow. Field Crops Research 52: 209-219.
87. Olsen, S.R., F.S. Watanabe, F.E. Clark, and W.D. Kemper. (1964). Effect of hexadecanol on evaporation of water from soil. Soil Science 97: 13-18.
88. Opoku, G. and T.J. Vyn. (1997). Wheat residue management options for no-till corn. Canadian Journal of Plant Science 77: 207-213.
89. Papendick, R.I. (1987). Tillage and water conservation; experience in the Pacific Northwest. Soil Use and Management 3: 69-74.
90. Pathak, P., S.M. Miranda, and S.A. El-Swaify. (1985). Improved rainfed farming for semi-arid tropics-implications for soil and water conservation. In Soil Erosion and Conservation, eds. S.A. El-Swaify, W.C. Moldenhauer, and A. Lo. Ankeny, IA: Soil Conservation Society of America, pp. 338-354.
91. Phene, C.J., R.J. Reginato, B. Itier, and B.R. Tanner. (1990). Sensing irrigation needs. In Management of Farm Irrigation Systems, eds. G.J. Hoffman. T.A. Howell and K.H. Solomon. St. Joseph, MI: American Society of Agricultural Engineering, pp. 208-261.
92. Piccolo, A., G. Pietramellara, and J.S.C. Mhagwu. (1996). Effects of coal derived humic substances on water retention and structural stability of Mediterranean soils. Soil Use and Management 12: 209-213.
93. Pikul, J.L., D.E. Wilkins, J.K. Aase, and J.F. Zuzel. (1996). Contour ripping: A tillage strategy to improve water infiltration Into frozen soil. Journal of Soil and Water Conservation 51: 76-83.
94. Plauborg, F. (1995). Evaporation from bare soil in a temperate humid climate-measurement using micro-lysimeters and time domain reflectometry. Agricultural and Forest Meteorology 76: 1-17.
95. Postel, S. (1997). Last Oasis: Facing Water Scarcity. New York, NY: W.W. Norton & Co.
96. Potter, K.N., H.A. Torbert, O.R. Jones, J.E. Matocha, J.E. Morrison, Jr., and P.W. Unger. (1998). Distribution and amount of soil organic C in long-term management systems in Texas. Soil & Tillage Research 47: 309-321.
97. Pressland, A.J. and G. N. Batianoff. (1976). Soil water conservation under cultivated fallows in clay soils of south-western Queensland. Australian Journal of Experimental Agriculture and Animal Husbandry 16: 564-569.
98. Ramig, R.E., R.R. Allmaras, and R.I. Papendick. (1983). Water conservation: Pacific Northwest, In Dryland Agriculture, eds. H.E. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 105-124.
99. Raper, R.L., J.H. Edwards, T.R. Way, B.H. Washington, E.C. Burt, and D.T. Hill. (1998). Effect of vertical trenching of cellulose waste on crop yield and hardpan reconsolidation. Transactions of the ASAE 41: 11-15.
100. Rawitz, E., J. Morin, W.B. Hoogmoed, M. Margolin, and H. Etkin. (1983). Tillage practices for soil and water conservation in a semi-arid zone. 1: Management of fallow during the rainy season preceding cotton. Soil & Tillage Research 3: 211-232.
101. Richardson, C.W. (1973). Runoff, erosion, and tillage efficiency on graded-furrow and terraced watersheds. Journal of Soil and Water Conservation 28: 162-164.
102. Sandal, S.K. and C.L. Acharya. (1997). Effect of conservation tillage on moisture conservation, soil-physical conditions, seedling emergence and grain yield of rainfed maize (Zea mays) and wheat (Triticum aestivum). Indian Journal of Agricultural Sciences 67: 227-231.
103. Schneider, A.D. (1999). Efficiency and uniformity of LEPA and spray sprinkler methods. Transaction of the ASAE vol. 42 (in press).
104. Schneider, A.D. and T.A. Howell. (1990). Sprinkler efficiency measurement with large weighing lysimeters. In Visions of the Future, Proceedings of the Third National Irrigation Symposium. St. Joseph, MI: American Society of Agricultural Engineers, pp. 69-76.
105. Schneider, A.D. and T.A. Howell. (1999). LEPA and spray irrigation for grain crops. Journal of Irrigation and Drainage Engineering 42: (in press).
106. Schneider, A.D. and A.C. Mathers. (1970). Deep plowing for increased grain sorghum yields under limited irrigation. Journal of Soil and Water Conservation 25: 147-150.
107. Sharma, K.D, N.S. Vangani, H.P. Singh, D.N. Bohra, A.K. Kalla, and P.K. Joshi. (1997). Evaluation of contour vegetative barriers as soil and water conservation measures in Arab lands. Annals of Arid Zone 36: 123-127.
108. Singh, S., S.K. Kaushik, and R.C. Gautam. (1997). Effect of tillage and moisture-conservation practices on productivity, water use and water-use efficiency of pearl millet (Pennisetum glaucum) on light soils under dryland conditions. Indian Journal of Agricultural Sciences 67: 232-236.
109. Smika, D.E. (1976). Seed zone soil water conditions with reduced tillage in the semiarid central Great Plains. In Proceeding of The 7th Conference of the International Soil Tillage Research Organization, Sweden, 1976, 6 pp.
110. Smika, D.E. (1983). Soil water change as related to position of wheat straw mulch on the soil surface. Soil Science Society of America Journal 47: 988-991.
111. Smika, D.E. (1986). Resources and problems in the central Great Plains. In Planning and Management of Water Conservation Systems in the Great Plains States, Proceedings of a Workshop, Lincoln, NE, October 1985. Lincoln, NE: U.S. Department of Agriculture, Soil Conservation Service, Midwest National Technical Center, pp. 39-55.
112. SSSA (Soil Science Society of America). (1996). Glossary of Soil Science Terms. Madison, WI: Soil Science Society of America.
113. Steppuhn, H. and J. Waddington. (1996). Conserving water and increasing alfalfa production using a tall wheatgrass windbreak system. Journal of Soil and Water Conservation 51: 439-445.
114. Stewart, B.A. (1988). Dryland farming: The North American experience. In Challenges in Dryland Agriculture - A Global Perspective, eds. P. W. Unger, T. V. Sneed, W.R. Jordan, and R. Jensen. College Station, TX: Texas Agricultural Experiment Station, pp. 54-59
115. Stewart, B.A., J.T. Musick, and D.A. Dusek. (1983). Yield and water-use efficiency of grain sorghum in a limited irrigated-dryland farming system. Agronomy Journal 75: 629-634.
116. Stroosnijder, B.A. and W.B. Hoogmoed. (1984). Crust formation on sandy soils in the Sahel. II. Tillage and its effect on the water balance. Soil & Tillage Research 4: 321-337.
117. Trout, T.J., R.E. Sojka, and R.D. Lentz. (1995). Polyacrylamide effect on furrow erosion and infiltration. Transactions of the ASAE 38: 761-765.
118. Twomlow, S., R. Riches, and S. Mabasa. (1997). Weeding-Its contribution to soil water conservation in semi-arid maize production. In Proceedings of The 1997 Brighton Crop Protection Conference-Weeds. Brighton, UK, pp. 185-190.
119. Tyler, D. (1998). Special issue on cover crops (Editorial). Journal of Soil and Water Conservation 53: 186.
120. Unger, P.W. (1978). Straw mulch rate effects on soil water storage and sorghum yield. Soil Science Society of America Journal 42: 486-491.
121. Unger, P.W. (1994). Tillage effects on dryland wheat and sorghum production in the southern Great Plains. Agronomy Journal 86: 310-314.
122. Unger, P.W. (1995). Role of mulches in dryland agriculture. In Production and Improvement of Crops for Drylands, ed. U.S. Gupta. New Delhi, Bombay, Calcutta: Oxford & IBH Publishing Co. Pvt. Ltd., pp. 241-270.
123. Unger, P.W. (1996). Common soil and water conservation practices. In Soil Erosion, Conservation, and Rehabilitation, ed. M. Agassi. New York, Basel, Hong Kong: Marcel Dekker, Inc., pp. 239-266.
124. Unger, P.W. (1997). Management-induced aggregation and organic carbon concentrations in the surface layer of a Torrertic Paleustoll. Soil & Tillage Research 42: 185-208.
125. Unger, P.W. and R.L. Baumhardt. (1999). Factors related to dryland grain sorghum yield increases, 1939 through 1997. Agronomy Journal (in press).
126. Unger, P.W. and B.A. Stewart. (1983). Soil management for efficient water use: An Overview. In Limitations to Efficient Water Use in Crop Production, eds. H.M. Taylor, W.R. Jordan, and T.R. Sinclair. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 419-460.
127. Unger, P.W. and M.F. Vigil. (1998). Cover crop effects on soil water relationships. Journal of Soil and Water Conservation 53: 200-206.
128. van Bavel, C.H.M. and R.J. Hanks. (1983). Water conservation: Principles of soil water flow, evaporation, and evapotranspiration. In Dryland Agriculture, Monograph 23, eds. H.E. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 25-34.
129. Van Doren, Jr., D.M. and R.R. Allmaras. (1978). Effect of residue management practices on the soil physical environment, microclimate, and plant growth. In Crop Residue Management Systems, ASA Special Publication Number 31, ed. W.R. Oschwald. Madison, WI: American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, pp. 49-83.
130. Vogel, H., I. Nyagumbo and K. Olsen. (1994). Effect of tied ridging and mulch ripping on water conservation in maize production on sandveld soils. Der Tropenlandwirt 95: 33-44.
131. Weakly, H.E. (1960). The effect of HPAN soil conditioner on runoff, erosion and soil aggregation. Journal of Soil and Water Conservation 15: 169-171.
132. Wicks, G.A. and D. E. Smika. (1973). Chemical fallow in a winter wheat-fallow rotation. Journal of the Weed Science Society of America 21: 97-102.
133. Wiese, A.F. (1983). Weed control. In Dryland Agriculture, Monograph 23, eds. H.E. Dregne and W.O. Willis. Madison, WI: American Society of Agronomy, Inc., Crop Science Society of America, Inc., and Soil Science Society of America, Inc., pp. 463-488.
134. Wiese, A.F., T.J. Army, and J.D. Thomas. (1966). Moisture utilization by plants after herbicide treatment. Weeds 14: 205-207.
135. Willcocks, T.J. (1984). Tillage requirements in relation to soil type in semi-arid rainfed agriculture. Journal of Agricultural Engineering Research 30: 327-336.
136. Wood, C.W., D.G. Westfall, and G.A. Peterson. (1991). Soil carbon and nitrogen changes on initiation of no-till cropping systems. Soil Science Society of America Journal 55: 470-476.
137. Zingg, A.W. and V.L. Hauser. (1959). Terrace benching to save potential runoff for semiarid land. Agronomy Journal 51: 289-292.