Influence of Tillage and Cropping System on Soil Quality and Crop Yield in North Carolina

Abstract

Reduced tillage crop production has been shown to improve characteristics of soil considered important in increasing productivity. However, these improvements do not always increase crop yield. Research in the southeastern region of the United States has documented benefits of perennial grass crops to increase soil quality and crop yield compared with conventional tillage systems and traditional reduced tillage systems. The economic value of these systems compared to traditional row crops each year influences the feasibility of this approach to crop production. Research evaluating this approach to crop production is limited in North Carolina. Research was conducted in North Carolina at four locations to compare yield of corn (Zea mays L.), cotton (Gossypium hirsutum L.), peanut (Arachis hypogaea L.), and soybean [Glycine max (L.) Merr.] when these crops were strip tilled following four years of tall fescue (Schedonorus phoenix Scop.) versus four years of either corn or cotton grown in no till or strip till (2005-2008). Cotton yield was higher following tall fescue while corn yield was lower when compared with planting following agronomic crops. Peanut was also planted in conventional tillage following both cropping systems with peanut yield in conventional tillage exceeding that of strip tillage. The peanut yield was higher in conventional tillage than reduced tillage regardless of cropping system. No major differences in bulk density were noted when comparing tall fescue and agronomic crops. Soil parasitic nematode populations, including lesion (Pratylenchus spp.), root knot nematode, Meloidogyne spp.), spiral (Helicotylenchus spp.), and stunt (Tylenchorhynchus sp.) were often lower following tall fescue versus agronomic crops with the exception of stubby root (Paratrichodorus spp.). These experiments demonstrated that sod based systems including tall fescue can improve cotton yield but would be of no direct benefit for peanut and soybean and a detriment to corn. Tomato spotted wilt virus (a Tospovirus) (TSWV) and Cylindrocladium black rot (Cylindrocladium parasiticum Crous, Wingfield, and Alfenas) (CBR) are important pests in peanut in North Carolina. Implementing integrated pest management (IPM) strategies for these pests in important because there is no corrective strategy once peanut is planted. Host-pant resistance is among the most important management tools to minimize adverse affects from these diseases. Tillage system is a component of TSWV management strategies and is one of five components of the TSWV risk index developed in North Carolina and Virginia for peanut. Although components of the TSWV risk index have been evaluated singly or as interactions, potential interactions of planting date and tillage have not been addressed in North Carolina. Do address this issue, research was conducted in North Carolina during 2008 and 2009 to define interactions of planting date (May 2-10 or May 25-28), tillage (conventional tillage or strip tillage following traditional agronomic crops, and Virginia market type cultivars (Bailey, CHAMPS, Gregory, Phillips, Perry, and VA 98R). A wide range of interactions were noted for plant condition, a visual estimate of disease reflecting CBR and TSWV expression in the peanut canopy, in mid September and within 3 days prior to digging cultivars at optimum maturity based on pod mesocarp color. Data for plant condition and pod yield were inconclusive with respect to clearly defining interactions among planting date, tillage, and cultivar. In some instances less disease, generally a combination of both CBR and TSWV, in reduced tillage compared with conventional tillage but this was not the case for all cultivars for all location and year combinations. Pod yield was lower in reduced tillage compared with conventional tillage in one of four experiments and at one planting date in second experiment; yield in reduced tillage did not exceed yield of conventional tillage. Although somewhat inconsistent, few differences in yield were noted when comparing planting dates. Differences in disease reaction reflected inherent resistance to disease for these cultivars. However, disease was not always uniform with respect to CBR and presence of TSWV was inconsistent. The objective of this research was to better define interactions among planting dates, tillage, and cultivars to improve recommendations on management of CBR and TSWV. However, additional research is needed to establish predictable trends in response to these factors in order to make effective recommendations for growers in North Carolina.

Description

Keywords

tall fescue, soybean, intergrated pest management, crop rotation, conservation tillage, peanut, cotton, peanut cultivar, planting date, corn

Citation

Degree

MS

Discipline

Crop Science

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