It took nearly 50 years to achieve food sufficiency in China. An
unanticipated cost has been that massive fertilizer inputs have led
to significant environmental degradation (6). Over-fertilization is a
serious problem in intensive agricultural production areas in China,
resulting in enrichment of reactive N in the air, soil and water with
consequent impairment of ecosystem services. Our studies show
that more efficient use of N fertilizer can allow current N application
rates to be reduced by 30 to 60%. This would still maintain crop
yields and N balance in rotations, while substantially reducing N
losses to the environment. The over-application ofNalso represents
an unnecessary economic expenditure for farmers. The new recommendations
should fully take into account the N supplying
capacity of the soil and N deposited from air and irrigation water.
The characteristics of N behavior among the 4 crops were sharply
different depending on climatic, soil and management practices.
This must be taken into consideration to further reduce N losses.
Only by reducing fertilizer N inputs can degraded environments be
gradually restored, enhanced and protected. Although several
environmental standards have been set in the past, there are still no
legislative controls in China equivalent to those in the European
Union (33). China would benefit from adopting and enforcing
relevant agricultural regulations (7). All these goals could be
achieved by removing government subsidies, introducing an N
fertilizer tax, improving local Extension Services, educating farmers
for environmental awareness, and employing practices that avoid
serious environmental degradation (43).
It took nearly 50 years to achieve food sufficiency in China. Anunanticipated cost has been that massive fertilizer inputs have ledto significant environmental degradation (6). Over-fertilization is aserious problem in intensive agricultural production areas in China,resulting in enrichment of reactive N in the air, soil and water withconsequent impairment of ecosystem services. Our studies showthat more efficient use of N fertilizer can allow current N applicationrates to be reduced by 30 to 60%. This would still maintain cropyields and N balance in rotations, while substantially reducing Nlosses to the environment. The over-application ofNalso representsan unnecessary economic expenditure for farmers. The new recommendationsshould fully take into account the N supplyingcapacity of the soil and N deposited from air and irrigation water.The characteristics of N behavior among the 4 crops were sharplydifferent depending on climatic, soil and management practices.This must be taken into consideration to further reduce N losses.Only by reducing fertilizer N inputs can degraded environments begradually restored, enhanced and protected. Although severalenvironmental standards have been set in the past, there are still nolegislative controls in China equivalent to those in the EuropeanUnion (33). China would benefit from adopting and enforcingrelevant agricultural regulations (7). All these goals could beachieved by removing government subsidies, introducing an Nfertilizer tax, improving local Extension Services, educating farmersfor environmental awareness, and employing practices that avoidserious environmental degradation (43).
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