I think we all agree that compost is good for the garden.
It adds organic matter that feeds the soil
Anecdotetally plants seem healthier with compost added? Or does is it mainly and adjunct by feeding the soil organisms the soil organisms in turn improve the growth and in turn keep the plants looking healthier.
https://www.uvm.edu/vtvegandberry/facts ... sttea.html
People have passionate opinions about compost and organic vs synthetic but research is difficult to do because of the inconsistent quality of most organic composts and fertilizers. It creates too many variables to control and makes the experiments difficult to repeat. Conclusions based upon a single test that is not reproduceable with many uncontrolled variables can be misleading or do not take into account that some other variable may be responsible for the result.
There can be a middle ground. organic and synthetic can cooexist and can be better together than used separately provided they are used correctly.
There is little composting research that is based on a long term study but I found one
https://www.ct.gov/caes/lib/caes/documen ... s/b966.pdf
1 Compost and some synthetic fertilizer usually a reduced rate had the highest yields followed by organic + organic fertilizers and no compost + synthetic fertilizer and the control was no compost
2 compost needs to be added every year and yields are best after three years of adding compost. However yields drop quickly if compost is not added. More needs to be added to sandy soils
3. On vegetable plots where compost alone was added for at least 3 consecutive years, yield was only 1 percent less than the unamended but fully fertilized control plot.
4. Compost added in the Spring was best. Soil organisms activity varies with temperature so they are less active in the fall and winter so release fewer nutrients.
5. Compost improves water holding capacity, but in soil that are wet when planted in the Spring they warm up slower and can hold too much water and increase seed rot.
6. 2 inches of compost can be applied as mulch for weed control although not 100% effective it does reduce weeds for up to a year.
7 Undecomposed leaves can be used as soil amendments. There is no gain over using composted leaves but no real detriments. However as the leaves decompose they may need more nitrogen fertilizer.
8. leguminous cover crops planted in the fall and compost applied with full rate fertilizer had the greatest yield in corn crops.
8 Manure based composts should be limited to 1 inch for 3 consecutive years to prevent nitrogen leaching. No manure in the fourth year.
9. Sheet mulching can grow a sufficient crop with the advantage of not having to maintain a compost pile. However yields are not as great as when compost is used.
10. Compost is not a fertilizer. Unlike inorganic fertilizers the nutrients in composts are not readily available to plants. However, soil organisms release nutrients from compost at a slower rate over a longer period of time. Nutrient release is dependent on organizms activity. Soil organisms release nutrients quicker in warm weather when plants are actively growing.
11. Synthetic fertilizers can be reduced by almost half if compost is also added every year.
12. Synthetic fertilizers increase yields but can also be detrimental to soil life in some circumstances but synthetic fertilizers are compatible with a healthy soil if everything is in balance.
https://www.agriculturesnetwork.org/maga ... ertilizers