The 2012 ASHS Annual Conference

This study evaluated two composts, leaf and yard waste (LY) and biosolids (BS) as soil amendments at three application rates on sweet corn production in an Agawam fine sandy loam during the 2010 and 2011 growing seasons.  In 2010, 80 lbs. of P₂O₅was broadcasted as recommended by soil tests.  No additional fertilizer was added in either year. BC 0805 sweet corn (82 days), was planted on 34” rows with a plant population of approximately 28,000 plants per acre. Composts were hand applied at the rates of 0, 10, 20, and 40 tons per acre and incorporated with a Perfecta harrow in three replicated plots. A cover crop of oats was planted in August of 2010 after harvest over the entire research area. In 2011, each plot was split in half.  One half received the same treatment as in 2010. The second half did not receive any additional compost or fertilizer.  Conventional herbicide weed control was implemented each year. Preside-dress Soil Nitrate Test (PSNT) values were used to evaluate the potential soil mineralization rate in both years.  In 2010, marketable yields were greater in plots receiving compost compared to the control. BS application rates of 20 and 40 tons/acre produced acceptable yields, 1069 and 1263 dozen per acre, respectfully. LY yields were consistently lower then acceptable yield levels of 1000 dozen per acre. All BS treatment yields were significantly higher in 2011 than in 2010.  LY compost yields were at or above acceptable yields. The yield increase was greater with multiple compost applications indicating an accumulative effect of compost in soils. Plots with no additional compost applications in 2011 had similar yield and PSNT values as 2010.  This indicates that the effects of compost last for at least two years and supports the idea that compost has a residual effect on the soil and crop productivity. Compost has a wide diversity of organic matter, from unstable to very stable; therefore mineralization happens over a longer period of time. Compost continued to feed the soil microbial population through year two. Both types of compost had a positive effect on the yield over a two year period and provided some plant available nitrogen in both application years.  Yields indicate both a cumulative and residual effect of compost.