000			02975nab a22003857a 4500
001			G91443
003			MX-TxCIM
005			20230825172655.0
008			200914s2008 ne |||p|op||| 00| 0 eng d
022			_a1385-1314
022			_a1573-0867 (Online)
024	8		_ahttps://doi.org/10.1007/s10705-007-9136-0
040			_aMX-TxCIM
041			_aeng
090			_aCIS-5412
100	1		_aMtambanengwe, F. _915811
245	1	0	_aSmallholder farmer management impacts on particulate and labile carbon fractions of granitic sandy soils in Zimbabwe
260			_aDordrecht (Netherlands) : _bSpringer, _c2008.
340			_aComputer File|Printed
500			_aPeer review
500			_aPeer-review: Yes - Open Access: Yes|http://science.thomsonreuters.com/cgi-bin/jrnlst/jlresults.cgi?PC=MASTER&ISSN=1385-1314
520			_aCrop production in maize-based smallholder farming systems of Southern Africa is hampered by lack of options for efficiently managing limited and different quality organic nutrient resources. This study examined impacts of farmers’ short- and long-term organic resource allocation patterns on sizes and quality of soil organic matter (SOM) fractions. Farmers’ most- (rich) and least- (poor) productive fields were studied for two seasons under low (450–650 mm yr-1) to high (>750 mm yr-1) rainfall areas in Zimbabwe, on Lixisols with -6% clay and 88% sand. Rich fields received 0.5–14 Mg C ha-1 compared with <4 Mg C ha-1 for poor fields, and the differences were reflected in soil particulate organic matter (POM) fractions. Organic inputs were consistent with resource endowments, with well-endowed farmers applying at least five times the amounts used by resource-constrained farmers. Rich fields had 100% more macro-POM (250–2,000 lm diameter) and three times more meso-POM (53–250 um) than poor fields. Application of high quality (>25 mg N kg-1) materials increased labile C (KMnO4 oxidizable) in top 60 cm of soil profile, with 1.6 Mg C ha-1 of Crotalaria juncea yielding labile C amounts similar to 6 Mg C ha-1 of manure. Labile C was significantly related to mineralizable N in POM fractions, and apparently to maize yields (P<0.01). Farmers’ preferential allocation of nutrient resources to already productive fields helps to maintain critical levels of labile SOM necessary to sustain high maize yields.
536			_aConservation Agriculture Program
546			_aText in English
591			_aSpringer
594			_aINT2737
650		7	_aMaize _2AGROVOC _91173
650		7	_aCrop yield _2AGROVOC _91066
650		7	_aOrganic matter _2AGROVOC _913683
650		7	_91763 _aSmallholders _2AGROVOC
700	1		_aMapfumo, P. _93354
773	0		_tNutrient Cycling in Agroecosystems _n635395 _gv. 81, no. 1, p. 1-15 _dDordrecht (Netherlands) : Springer, 2008. _wu63406 _x1385-1314
856	4		_uhttps://hdl.handle.net/20.500.12665/81 _yAccess only for CIMMYT Staff
942			_cJA _2ddc _n0
999			_c27327 _d27327