What type of fertilizers create best food production with least environmental impact? Organic or Chemical?

Question

does using "green manure" yield just as much or more crops than chemical fertilizers.

Answer 1

Organic fertilizers are a great idea but if the entire US switched, we'd starve to death.  There just isn't enough p**p out there to satisfy nitrogen needs.  Commercial fertilizers are actually vrey natural.  

Urea or ammonium nitrate is made by combining atmospheric nitrogen with carbon from natural gas.  

Phosphrous is mined from the soil in Florida and Alberta.  "Super" phosphate is made by treating rock phosphate with sulfuric acid to concentrate it.

Potash is mined in Canada, sw US and Chile.  So actually, those fertilizers are organic.

And the safer business?  I don't know of any cases where our food supply has been deemed unsafe by using commercial fertilizers.  Organic sure has, remember the E coli spinich from California?  The fields were fertilized with cow manure.  World travelers know better than to eat root crops from places like China and the Nile Delta of Egypt because of the use of human waste or sewage in raising the crops.  Given the choice, I'll use commercial fertilizers any day.

Answer 2

organic

Answer 3

Cowboy is right on track!  

I will add that a lot of the differences in yield between organic and chemical agricultural production come down to culture and growing techniques.  For instance, organic production tends to be done in much smaller fields, uses a lot less machinery, and requires a lot more physical labor.  So organic produce, especially locally grown, tend to be ripened on the vine longer and handled more by hand and less by machine resulting in less damage.  

So when looking at this question be sure you are looking at just the fertilizer and not the growing techniques that are often associated with them.

Answer 4

maybe not as much but safer

Answer 5

Green manures tend to hold nitrogen in them longer, so in the end stages when you need less nitrogen, you're crops will get too much

Answer 6

Using green manure alone will not yield as much as using chemical fertilisers and good organic fertility would involve much more. Compost, kelp, rock powders, peat moss are other inputs used in fertility and over several years can indeed yield as much or more as chemical fertilisers as well as use less water and have far less impact on the environment.

Answer 7

organic is much better for the environment.  there are organic farms that out produce conventional chemical farms, although it isn't the norm.  to produce the bumper crop organically it takes a lot of know how. green manure is great but to get the big yields you will probably need an additional nitrogen source. green manure will break down slowly in the soil giving a more constant nutrient source, but you should apply a faster acting source at certain growth stages to maximize potential yield.

Answer 8

If you want high potent fertilizer, use chicken manure, but use sparingly as this is and makes the best grown crops. To use this, spread on ground and work into the soil . then plant your crops or gardens.

Answer 9

It may not be the most effecient, but if your looking at the Enviromentally correct thing to do this yes it is. But chemical fertilizers are not bad for the enviroment if properly used and watched.

Answer 10

Organic fertilizers can produce almost as much yield as chemical fertilizer if applied at a high enough rate.  Unfortunately that would require a very high rate of application and would be expensive and could burn the crops.  So traditional fertilizers usually produce higher yields than organic fertilizers.  Organic fertilizers break down slowly and as such are less threat to the environment than chemical fertilizers that if used incorrectly can cause run off into streams and get into the ground water.  Organic fertilizers such as barn yard manure can also run off the fields and contaminate streams and find their way into ground water with bacteria and nitrates as well, if not handled properly.   Green manure crops are planted for two main reasons, first to help control erosion during winter where the land would be bare and susceptible to erosion and second to release nutrients to the soil as it breaks down from organic matter.  It breaks down slowly and in the early stages can use more nitrogen than it supplies.  In the long run green manure crops are very good for the environment, but it is not a replacement for fertilizers.