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003 MX-TxCIM
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020 _a971-22-0060-4
040 _aMX-TxCIM
082 0 4 _a95-130353
100 1 _aGarrity, D.P.
110 2 _aInternational Rice Research Conference. Los Banos, Laguna (Philippines). 1992
245 0 0 _aPrerice green manure production in rainfed environments:
_b a simulation approach
260 _c1994
340 _aPrinted
500 _a2 charts; 10 graphs; 4 tables; 8 ref. Summary (En) AIBA-SEARCA, College, Laguna 4031 - Philippines
520 _aThe rainfed lowland ricelands prone to waterlogging in the prerice season are a major potential area for growing green manure (GM) crops tolerant of saturated soils. But year-to-year variability in GM growth and N accumulation would be large due to widely varying field hydrology in the dry-to-wet transition months. A simulation model of the GM-rainfed rice system was developed to estimate the yields and relative stability of prerice GMs and the subsequent rice crops at three representative sites in Southeast Asia. Average estimated N yield and yield stability over 26 yr were higher at Los Banos, Laguna, Philippines, than at Ubon, Thailand, or Tuguegarao, Philippines. The effects of planting date on sesbania N accumulation and following rice yields were compared: the late-planted (at 100 mm cumulative rainfall) crop accumulated more N than did the early- planted (at 50 mm rainfall) one because of higher soil moisture. Yields of following rice were similar for both sesbania planting dates, indicating that late planting of GM would not reduce rice yields. Optimum N rates for rice were also similar for both planting dates; consequently, more purchased N would be needed for rice following early-planted sesbania. The costs per unit of green manure N were higher than those of urea N when full wage rates and intensive tillage were assumed. However, with zero tillage and/or a modest cumulative soil fertility benefit, the cost of green manure N would be similar to or lower than that of urea N. The implications of these findings for future research are discussed
546 _aEnglish
595 _aAC
650 1 0 _aAsia
650 1 7 _aCrops
_gAGROVOC
_2
_91069
650 1 0 _aCultural methods
650 1 7 _aFertilizers
_gAGROVOC
_2
_91111
650 1 0 _aFertilizing
650 1 0 _aGramineae
650 1 0 _aLeguminosae
650 1 0 _aMathematical and statistical methods
650 1 0 _aMathematical models
650 1 0 _aModels
650 1 0 _aOrganic fertilizers
_91740
650 1 0 _aOryza
650 1 0 _aPapilionoideae
650 1 0 _91313
_aYields
_gAGROVOC
700 1 _aFlinn, J.C.,
_ecoaut.
773 0 _tLadha, J.K.; Garrity,-D.P. (eds.). International Rice Research Inst., Los Banos, Laguna (Philippines). Green manure production systems for Asian ricelands: selected papers from the International Rice Research Conference. Los Banos, Laguna (Philippines). IRRI. 1994. p. 11-26. Received Apr 1995. (UPLB Acc. no. 119007)
942 _cREP
999 _c5684
_d5684