That's so there's room to keep lots of stuff up them.

Diversified, low-external-input (LEI) farming systems offer one possible approach for maintaining adequate productivity and profitability while reducing pollution by agrichemicals and still improving water quality.

Sounds kind of good, but what does adequate mean. In a world where there is a large and growing shortfall in ag production this doesn't sound so good after all.

Conventional rates of synthetic fertilizers were applied in the two-year rotation, whereas composted cattle manure and reduced rates of synthetic fertilizers were applied in the three- and four-year rotations.

Where did the manure come from? How was it produced? Isn't this just a hide-the-pea game again, a way to sneak fertilizer in by having some other grower launder it, like gangsters do with money by passing it through dummy corporations or offshore banks before they spend it at home?

Weed management in the two-year rotation was based on conventional rates of herbicides, whereas in the three- and four-year systems, herbicides were applied in bands in corn and soybean, greater reliance was placed on cultivation, and no herbicides were applied in small grain and forage legume crops.

Is cultivation low input? Is it even a good thing given the harm it does to soil quality? Doesn't it contribute to wind and water erosion as well as GHG emissions?

The objective of producing high yields with the least costs - in every sense, considering often disregarded externalities such as environmental harm - is worth while, it's what every grower does for a living. But researchers don't help when they aren't honest.

There isn't enough manure in the world to replace manufactured nutrients. It's worth about 10% if used wisely. Crop stubble and ag trash are worth more, but in both cases the real benefit isn't the fertilizer, it's the effects on soil structure and quality. Growers would benefit from it even if it had no fertilizer at all since it can help make more effective use of the fertilizer they apply, in part by holding nutrients in the root zone longer so that plants can use them.

In the past it was often more expensive to haul the large amounts of organics to the land and then spread it than to use manufactured nutrients. It is getting ever more expensive as fuel prices rise. But the cost of manufactured nutrients are rising too, and are likely to continue to do so. There may be some break even point where the cost of fuel, though high, is less than the cost of manufactured inputs.

This won't help much since there isn't much manure. In the end it's a make or buy decision: is it better for a grower to buy organics to amend land or grow it in place? Given that there isn't enough organics on the market for everyone to buy, the vast majority will have to be made on site.

Researchers would be more useful if they sought to quantify such real world issues rather than doing phony grade-school experiments.