Rowcovers and Strip Tillage Provide an Alternative to Plasticulture Systems in Summer Squash Production

Abstract

<jats:p>Plastic mulch is often used in cucurbit production, but it has negative soil health and environmental implications due to use of tillage for installation and generation of plastic waste. This 2-year study aimed to find a viable alternative to plastic mulch through the use of strip tillage and rowcovers, as rowcovers could help minimize yield loss from strip tillage by providing warmer air and soil as well as providing insect protection. A split-plot design was used in both conventionally and organically managed summer squash (<jats:italic>Cucurbita pepo</jats:italic>), with production system as the whole-plot factor [conventional tillage with black plastic mulch also referred to as plasticulture (PL) and strip tillage into rolled cereal rye (S<jats:italic>ecale cereale</jats:italic>) (ST)] and rowcover use as the subplot factor (rowcover until anthesis or no rowcover). Rowcovers reduced the incidence of squash vine borer (<jats:italic>Melittia cucurbitae</jats:italic>) and eliminated the need for insecticide sprays to control this insect pest, but did not reduce the incidence of yellow vine decline or the sprays needed to control squash bug (<jats:italic>Anasa tristis</jats:italic>). Rowcovers increased average air temperature by 1.6 to 4.0 °C and increased maximum air temperature by up to 10.3 °C. Rowcovers decreased average light intensity by 33% to 39%. Though soil temperature in PL tended to be higher than in ST, in 1-year rowcovers helped bridge the gap. Plant biomass was consistently higher in the PL than the ST system. Averaged across rowcover treatments, plants in PL had higher marketable yields than those in ST; however, the use of rowcovers often led to comparable yields between the production system treatments. Rowcover was a significant factor explaining marketable yield for the organically managed fields both years. There was no consistent effect of production system on soil microbial biomass carbon (MBC). Based on our results, strip tillage into rolled rye could be a viable alternative to plasticulture for summer squash production in Iowa, and rowcovers could help increase yields in ST especially in an organic management system.</jats:p>

Integrating Rowcovers and Strip Tillage for Pest Management in Summer Squash and Muskmelon Production

“…Strip tillage underperformed in both years of the study compared with plasticulture, and it resulted in significantly reduced summer squash and muskmelon yields. Although conservation systems have the potential for yields comparable to those of conventional tillage (Hoyt, 1999;NeSmith et al, 1994;Tillman et al, 2015a), this was not observed in our study. SOIL MANAGEMENT SYSTEM.…”

“…Marketable yields and pest numbers were generally greatest in the plasticulture systems for both the summer squash and muskmelon studies in 2013 and 2014. Previous studies also showed increased yields in plasticulture systems compared with other tillage practices (Lilley and S anchez, 2016;Mahadeen, 2014;Parmar et al, 2013;Tillman et al, 2015aTillman et al, , 2015b, and pest pressure is often greater in conventionally tilled crops than in reduced tillage systems (Cheshire and All, 1979;Dieterich-Mabin, 2017;Stinner and House, 1990).…”

“…Plasticulture contributes to increased yields by increasing soil temperatures, resulting in increased plant biomass and yield in cucurbit systems (Baker and Reddy, 2001;Jenni et al, 1996;Tillman et al, 2015a). Strip tillage has been shown to decrease soil temperatures and increase soil moisture, which can impede vine growth and yield in cucurbit crops (Hoyt et al, 1994;Johnson and Hoyt, 1999;Tillman et al, 2015aTillman et al, , 2015bVerhulst et al, 2010). Plasticulture resulted in greater marketable yields of both the summer squash and muskmelon.…”

“…Strip tillage is a form of conservation tillage that reduces the disruption of the soil and increases microbial biomass by only disrupting narrow strips with tillage for planting and leaving the remaining area untilled (Aziz et al, 2013;Hoyt et al, 1994;Kladivko, 2001;Lupwayi et al, 1998;Stinner and House, 1990). This can result in yields equivalent to those of conventional tillage systems for summer squash (NeSmith et al, 1994;Tillman et al, 2015a), but it can be challenging for muskmelon production (Skidmore et al, 2017;Tillman et al, 2015b) because fruit in direct contact with soil is more susceptible to damage and disease. Plasticulture is a management system that uses conventional tillage with plastic-covered raised beds.…”

Citizen science improves our understanding of the impact of soil management on wild pollinator abundance in agroecosystems

“…Strip-tillage is often accompanied by the presence of cover crop residues (mulch) between strips of tilled soil which can help maintain soil moisture, reduce soil erosion, and inhibit weed seed germination [56]. We did not observe a significant decrease in average squash bee visitation where mulch was present, but rather a numerical increase.…”