The bane of environmental activism and reporting is the arrogant, authoritarian mindset of those who self select to be involved in such pseudo-professions. Every dollop of information is poorly analyzed and coupled with nonsensical policy prescriptions.

researchers . . . found that using 30-60% less nitrogen kept crop yields the same but halved nitrogen loss to the environment. The team studied two double-cropping systems – waterlogged rice/upland wheat in the Taihu region of east China and irrigated wheat/rainfed maize on the North China Plain.

All four crops showed different nitrogen behaviour, "depending on climatic, soil and management practices". The team calculated that the rice/wheat system had an annual nitrogen surplus of 87 kg per hectare. This system had large losses by denitrification, which the scientists reckoned could be reduced by improving carbon management and controlling the water regime.

The wheat/maize system had a 212 kg per hectare nitrogen surplus and large nitrogen losses from ammonia volatilization. The researchers say that changing nitrogen application techniques and using deep placement of urea or ammonium bicarbonate could substantially reduce ammonia volatilization losses from calcareous soils. Current agricultural practices use 550-600 kg of nitrogen per hectare.

"A better nitrogen balance can be achieved without sacrificing crop yields but significantly reducing environmental risk by adopting optimum nitrogen fertilization techniques, controlling the primary nitrogen loss pathways and improving the performance of the agricultural Extension [advisory] Service," said Ju. "The over-application of nitrogen also represents an unnecessary economic expenditure for farmers."

Emphasis added. Keep in mind.

All these goals could be achieved by removing government subsidies, introducing a nitrogen fertilizer tax, improving local Extension Services, and educating farmers for environmental awareness.

The only change required is to remove subsidies. That alone will provide all of the motivation required for farmers to become wiser about fertilizer use. No regulations, taxes, or bureaucratic meddling is required. There is a role for government in supporting research to establish true crop requirements, field methods to measure and monitor soil chemistry, manufacturing methods for modern advanced fertilizers, and making such information widely available.

Taxes are merely ways to extract wealth from farmers. Regulations are merely jobs programs for connected constituencies. Extension services are also jobs programs unless they are controlled and funded by the farmers themselves so that the incentives and accountability are properly aligned. Often the best extension agents are local master farmers who spend some of their later years teaching to others the lessons learned during a lifetime of work.

It's useful to reflect on the causes of current problems. In nearly every case the problems were caused by government meddling, and the fix is to stop meddling, not meddle more vigorously. When farmers once again earn their livings by farming the land rather than kowtowing to government bureaucrats then farming systems will become more rational.