Effect of planting season and type of fertilizer on biomass yield and quality of sugar cane; results for two years

摘要

Threetreatmentswerecompared:plantingatmonthlyintervalsfromJune1994throughtoMay1995;mulchingornomulchingwiththedeadleaves;andorganic(cattle)manureorchemicalfertilizer.Theexperimentaldesignemployedmonthlyplantingasmainplots,mulchingornomulchingassplitplotsandfertilizertypeassplit-splitplots.Thispapersummarisesresultsforthesecondharvestwhichwasdone12monthsafterthefirstharvest.Fertilizertreatmentsandmanagementwerethesameasinthefirstyear.Thetwofertilizerregimeswere:organic(fromcattle)manure(20tonnes/ha)orchemicalfertilizers(150Nasurea,100P205,200K20kg/ha)ascontrol.Mulchingconsistedofdetachingthedeadleavesandleavingthemonthesoilsurfaceorremovingthemfromtheplotatmonthlyintervalsbeginning6monthsafterthepreviousharvest.Theureawasgiveninthreeapplications(at1month,3monthsand5monthsafterfirstharvest).Phosphoruswassuppliedafterharvest.Manureandpotassiumwereintwodressings(75%afterharvestand25%5monthslater).Theplantingmaterialwasstemcuttings(30cmlength)intwocontinuousrowsperfurrow.Overallpopulationsdecreasedfromthefirsttothesecondyear.Therewasastrongindication(P=0.06)thatthemanuretreatmentsupportedahigherplantpopulationthanthechemicalfertilizers.Theyieldofediblebiomass(stalks,topsandgreenleaves)whichcanbeusedforfeedinganimalswashigherinthesecondthaninthefirstyear,probablybecauseofthebetterclimaticconditionsforplantgrowth.Thepatternofyieldwassimilarinbothyearswithhighestyieldsforplotsestablishedinthetraditionalseason(January-July).Mulchingincreasedyieldby8%inthefirstharvestandby15%inthesecondharvest.Itisconcludedthatyear-roundplantingofsugarcane,althoughnotrecommendedforsucroseprooduction,isneverthelessfeasiblewhenthecropistobeusedaslivestockfeed.