000			01665nab a22003737a 4500
001			G33940
003			MX-TxCIM
008			121211b |||p||p||||||| |z||| |
040			_aMX-TxCIM
041	0		_aEn
043			_aUS
072		0	_aP36
090			_aREP-4245
100	1		_aDaniels, R.B.
245	0	0	_aQuantifying the effects of past soil erosion on present soil productivity
260			_c1987
340			_aPrinted
500			_aGraphs, references cited p. 186-187
520			_aMost research relating crop productivity to soil erosion has been based on two assumptions: all soil properties of the experimental site were similar when first cultivated and the productivity of the site was uniform until erosion occurred. This approach relates any reduction in yield on eroded sites to erosion severity. Both assumptions usually are false because soil variabilty is high in landscapes subject to moderate to severe erosion when cultivated. Most gently rolling landscapes were shaped by erosion even before they were cultivated. Within such landscapes, soil properties differ in texture from the original soil material, as well as duration of
546			_aEnglish
595			_aRPC
650	1	0	_aErosion _91961
650	1	0	_aPhysiographic features
650	1	0	_91824 _aSoil chemicophysical properties _gAGROVOC
650	1	0	_aSoil resources
650	1	0	_aSoil structure
650	1	0	_aSurveys
650	1	0	_91952 _aSoil fertility _gAGROVOC
700	1		_aCassel, D.K., _ecoaut.
700	1		_aGilliam, J.W., _ecoaut.
700	1		_aNelson, L.A., _ecoaut.
773	0		_tJournal of Soil and Water Conservation _n617612 _gv. 42, no. 3, p. 183-187
942			_cJA
999			_c12242 _d12242