000			02991nab|a22003137a|4500
999			_c62163 _d62155
001			62163
003			MX-TxCIM
005			20211006085211.0
008			200624s2011||||ne |||p|op||||00||0|eng|d
022			_a0168-1923
024	8		_ahttps://doi.org/10.1016/j.agrformet.2011.02.010
040			_aMX-TxCIM
041			_aeng
100	1		_aSacks, W.J. _914371
245	1	0	_aCrop management and phenology trends in the U.S. Corn Belt : _bimpacts on yields, evapotranspiration and energy balance
260			_aAmsteram (Netherlands) : _bElsevier, _c2011.
500			_aPeer review
520			_aCrop yields are affected by many factors, related to breeding, management and climate. Understanding these factors, and their relative contributions to historical yield increases, is important to help ensure that these yield increases can continue in the future. Two important factors that can affect yields are planting dates and the crop's growing degree day (GDD) requirements. We analyzed 25 years of data collected by the USDA in order to document trends in planting dates, lengths of the vegetative and reproductive growth periods, and the length of time between maturity and harvest for corn and soybeans across the United States. We then drove the Agro-IBIS agroecosystem model with these observations to investigate the effects of changing planting dates and crop GDD requirements on crop yields and fluxes of water and energy. Averaged across the U.S., corn planting dates advanced about 10 days from 1981 to 2005, and soybean planting dates about 12 days. For both crops, but especially for corn, this was accompanied by a lengthening of the growth period. The period from corn planting to maturity was about 12 days longer around 2005 than it was around 1981. A large driver of this change was a 14% increase in the number of GDD needed for corn to progress through the reproductive period, probably reflecting an adoption of longer season cultivars. If these changes in cultivars had not occurred, yields around 2005 would have been 12.6 bu ac−1 lower across the U.S. Corn Belt, erasing 26% of the yield increase from 1981 to 2005. These changes in crop phenology, together with a shortening of the time from maturity to harvest, have also modified the surface water and energy balance. Earlier planting has led to an increase in the latent heat flux and a decrease in the sensible heat flux in June, while a shorter time from maturity to harvest has meant an increase in net radiation in October.
546			_aText in English
650		7	_aMaize _gAGROVOC _2 _91173
650		7	_aSoybeans _2AGROVOC _93639
650		7	_aPlanting date _2AGROVOC _93766
650		7	_aCrop yield _gAGROVOC _2 _91066
650		7	_aAgroecosystems _2AGROVOC _96058
650		7	_aModelling _2AGROVOC _911710
700	1		_aKucharik, C.J. _914372
773	0		_gv. 151, no. 7, p. 882-894 _dAmsteram (Netherlands) : Elsevier, 2011. _x0168-1923 _tAgricultural and Forest Meteorology _wu444454
942			_cJA _n0 _2ddc