| The effects of nitrogen fertilization on grain mineral concentrations of maize varieties fromdifferent eras were investigated under field conditions in Northeast China in2010. The plant densitywas52500plants ha-1with four N application rates conducted in this experiment, including no Napplication （CK）,150kg N ha-1（N1）,300kg N ha-1（N2） and450kg N ha-1（N3）. The concentrations ofFe, Mn, Cu, Zn, Ca, Mg and P in the grains were determined. At the same time, the concentrations of Fe,Mn, Cu and Zn were determined in the whole grain and its fractions for the Zhengdan958fromLiaoning province so as to learn the differences in the mineral contrentraion reponses between thedifferent fractions of maize grain. Our results indicated that:（1） During the period1950s to2000s, the grain Mn, Zn and Cu concentration in Northeast Chinadecreased significantly, the grain Ca and Mg concentration also showed decreasing trend except thegrain Mg concentration in Liaoning Province and Ca concentration in Jilin province. The Znbioavailability of the average of three province, Jilin province and Liaoning province decreased over thetime of the varietieas released. The Zn bioavailability of Heilongjiang province was highest in1960svarieties, but there was no obvious difference in the other eras. The Fe bioavailability of Jilin provincebegan to decrease from1980s, and the Fe bioavailability of Liaoning province increased over the eras,while the Fe bioavailability of Heilongjiang province show no obvious difference over the eras. The Cabioavailability of Jilin province in1970s,1990s and2000s varieties were lower than in1960s and1980svarieties, and Ca bioavailability of Liaoning province in1970s varieties were higher than in the othereras varieties, while the Ca bioavailability of Heilongjiang province began to decease from1970s. Therewas no obvious difference of Mg bioavailability over the eras.（2） The Zn concentration in Heilongjiang province decreased by N application，while the Znconcentration in Jilin province and Liaoning1960s varieties increased by N fertilization. The result ofthe average of three provinces indicated that Fe concentration in1980s and2000s varieties decreased byN appilication and Fe concentration in1970s and1990s varieties firstly increased and then decreased byN fertilization. The Fe concentration in1990s and2000s varieties of Heilongjiang province increased byN application, the Fe concentration in1980s varieties of Jinlin province and in Liaoning provincedecreased by N fertilization, while Fe concentration in1970s,1990s and2000s varieties of Jilinprovince firstly increased and then decreased by N application. The Mn concentration increased and Cuconcentration decreased by N application in the average of three provinces and all the three provinces.The results in the average of three provinces and all the three provinces showed that in most varieties Caconcentration decreased and Mg concentration increased by N application. The grain Zn, Fe and Cabioavailability decreased by N application. The Mg bioavailability in Heilongjiang and Jinlin provincesdecreased by N fertilization, but Mg bioavailability in Liaoning province showed no obvious differenceto N application.（3） In the whole grain, Fe, Zn, Mn and Cu concentrations were significantly increased byapplication of N fertilizer from N0to N2, but concentrations tended to decrease by increasing the N rate from N2to N3even the Cu concentration was reduced significantly. Application of N has differenteffects on the micronutrients concentration of maize grain fractions. The endosperm Fe, Zn, and Mnconcentrations were increased by increasing N supply but did not differ between N2and N3treatments,while Cu concentrations was not significantly different rang from N0to N2, but the concentration in N3was significantly higher than in N0and N1. As for pericarp, increasing the N supply enhanced the Mnconcentration but did not significantly affect other pericarp micronutrients concentration. Theconcentrations of Fe, Zn, and Cu but not for Mn in embryo were decreased significantly by increasing Nfertilizer. N fertilization significantly increased endosperm Fe, Zn, Mn, and Cu percentages; althoughpericarp micronutrients percentages were also increased by N supply but only pericarp Mn percentagewas enhanced significantly. However, the embryo Fe, Zn, Mn, and Cu percentages were negativelyaffected by N fertilization. Our result indicated that N application promoted micronutrientsaccumulation in endosperm and pericarp. |
PDF Full Text Request