#########################################################

A long-term program comparing effects of organic and conventional methods on vegetable production was begun in 2002.  The conventional method employs synthetic fertilizers and pest control methods.  The organic method employs organically certified fertilizers and pest control methods.  Bell pepper, cucumber and sweet corn are the crops being examined.  In the organic plots, in addition to the fertilizer applied to all plots, levels of humates (Hum) and corn gluten meal (CGM) were also applied.  The humates were applied and incorporated prior to planting.  The CGM, which is an organic herbicide and also supplies additional nutrition, was applied after the vegetable crops had established root systems.  The rates for humate were: 0 = none applied, 1 = 100 lbs/acre; 2 = 200 lbs/acre; and for CGM were: 0 = none applied; 1 = 400 lbs/acre; 2 = 800 lbs/acre.

                                                                                   Yields in Tons/acre

Rates for Hum (humate): 0 = none applied, 1 = 100 lbs/acre; 2 = 200 lbs/acre; and for

CGM (corn gluten meal): 0 = none applied; 1 = 400 lbs/acre; 2 = 800 lbs/acre.

Total yields for the first three years favor the conventional methods.  However, yields for organic production improved in 2003 and 2004 appeared to be higher than those for the conventional production.  The two organic treatments with the highest yields are expressed in bold italic. There did not appear to be a pattern in yield associated with the organic treatments between years.

                                                                                    Yields in Tons/acre

Rates for Hum (humate): 0 = none applied, 1 = 100 lbs/acre; 2 = 200 lbs/acre; and

Total yields for the first three years favor the conventional methods.  However, yields for organic production improved in 2003 and was close to that of the conventional system in 2004.  The two organic treatments with the highest yields are expressed in bold italic. Only for Hum:CGM treatment 2:0 did there appear to be a pattern in yield associated with treatment between years.

                                                                                         Yields in Tons/acre

Rates for Hum (humate): 0 = none applied, 1 = 100 lbs/acre; 2 = 200 lbs/acre; and

CGM (corn gluten meal): 0 = none applied; 1 = 400 lbs/acre; 2 = 800 lbs/acre.

Total yields for the first three years favor the conventional methods.  Yields for organic production in 2002 appeared to be similar to those for 2003, but were generally higher in 2004.  The two organic treatments with the highest yields are expressed in bold italic.
 

#########################################################
 

Use of Manure in Organic Vegetable Production

Manure is a renewable fertilizer that provides several benefits in organic vegetable production. Unless it is produced on site it is a commodity that must be moved to the place where it is being used. This can increase cost of usage. Following the completion of the transition period a four-year study examined the application of manure annually or biennially with comparison to conventional production of bell pepper, pickling cucumber and sweet corn. Yields between organic and conventional production methods for all crops were similar; differences in profit were affected by inputs. This project took place from 2005 to 2008 and the full text of the article can be found in the publications list under the section titled Organic.

All organic treatments produced yields that were superior to conventionally produced crops. Generally it was necessary to apply manure annually to maximize profits. The only exception was biennial application of manure to cucumber where profits exceeded those of annually applied manure. It appears that it is necessary to apply manure annually. Although there is an annual input required the use of manure can provide benefits to the soil. The main concern with annual manure usage is the accumulation of phosphorus in the soil. It this occurs it will likely be necessary to apply materials, other than manure, that specifically provide nitrogen and potassium until the phosphorus level is brought down. Some crops are better miners of phosphorus than others and may be used to reduce phosphorus level.

Difference in profit, after 4-years, for bell pepper due to application of
manure annually or biennially compared to conventional production.

Difference in profit, after 4-years, for cucumber due to application of
manure annually or biennially compared to conventional production.

Difference in profit, after 4-years, for sweet corn due to application of
manure annually or biennially compared to conventional production.

#########################################################
 

Use of Microbial Amendments in Bell Pepper Transplant Production

The beneficial relationship of certain bacteria and legumes under field production is well known.  Use of soil amendments containing microbials have been described as being beneficial to plant development.  Generally these products, mixtures of bacteria and/or fungi, are applied to the soil in field production.  It is less clear what benefits may occur if they are used in the production of vegetable transplants.  The benefit to organic production of vegetable transplants needs clarification.  This project was conducted in 2005 and the full text of the published article is found under the publications list in the section titled Organic.

A greenhouse experiment that replicated commercial production of bell pepper transplants was initiated using 128 cell transplant trays.  An O.M.R.I. certified potting mix was used and inoculated with commercially available mixes of bacteria or mixes of fungi.  The bacterial mix is normally used with legumes.  The fungal mix contains propagules of mycorrhizal fungi.  Bell pepper seed, cv. Jupiter, were placed in the moistened potting mix.  Each treatment (bacteria or fungi) had un-inoculated potting mix as controls.  All plants were also treated with various doses of an O.M.R.I. certified fertilizer and irrigated either twice of three times a day.

Heights and dry weights of transplants treated with mixes of bacteria.

Heights and dry weights of transplants treated with mixes of fungi.

#########################################################
 

Inoculation of Bell Pepper Transplants and Field Response

Effectiveness of microorganisms applied in production of organic vegetables has had mixed results.  It was determined that beneficial bacteria applied to a potting mix appeared to improve development of bell pepper transplants.  The application of microbial amendments in bell pepper transplant production was extended to determine if effects begun in the greenhouse could be continued in the field.  Conventionally produced bell pepper transplants were compared to bell pepper transplants produced with inoculation of the medium with mixes of bacteria, mixes of fungi and mixes of both bacteria and fungi.  Conventional and organically produced transplants were established in Stigler (clay loam) and Bernow (sandy loam) soils and plants were grown with conventional or organic protocols and materials.  This project took place between 2006 and 2008 and the full text of the report is found in the publications list under the section titled Organic.

Yield of bell pepper on a Stigler and Bernow soil using conventional and
organic production methods.