Problems arising from conventional tillage (CT) systems (such as soil erosion, decrease of organic matter, environmental damage etc.) have led many farmers to the adoption of no-till (NT) systems that are more effective in improving soil physical, chemical and microbial properties. Results from this study clearly indicated that NT, mulch tillage (MT), and winter rye cover cropping systems increased the activity of phosphatase, β-glucosidase and arylsulfatase at a 0–10 cm soil depth but decreased the activity of these enzymes at 10–20 cm. The increase in enzyme activity was a good indicator of intensive soil microbial activity in different soil management practices. Poultry litter (PL) application under NT, MT, and rye cropping system could be considered as effective management practices due to the improvement in carbon (C) content and the biochemical quality at the soil surface. The activities of the studied enzymes were highly correlated with soil total nitrogen (STN) soil organic carbon (SOC) at the 0–10 cm soil depth, except for acid phosphatase where no correlation was observed. This study revealed that agricultural practices such as tillage, PL, and cover crop cropping system have a noticeable positive effect on soil biochemical activities under cotton production

Organic farming is currently the fastest growing agricultural sector worldwide. However, diseases and weeds are among the major factors limiting its expansion. The use of cover crops has been shown to reduce weeds and minimize soil-borne pathogen populations through increased organic matter deposition, which also improves soil structure and porosity. Reflective and colored plastic mulches have also been shown to reduce vector borne diseases on many vegetable crops, including tomato. Such measures to combat disease depend on other variables and are generally site-specific. Two experiments were conducted to evaluate the effects of the winter cover crops, crimson clover, rye, hairy vetch, and Austrian winter peas and reflective polyethylene mulch with or without biofungicides on severity of diseases and fruit yield of tomato. Plant height, fruit weight, number of fruits per plant and the type of foliar and fruit diseases observed including their severity were determined. Tomato fruit rot incidence was significantly lower in tomato plants grown following hairy vetch and Austrian winter pea compared to plants in fallow plots. Reflective polyethylene mulch was significantly (p = 5%) better than control (no mulch) for fruit yield, number of fruits/plant and plant height. However, plants on reflective polyethylene mulch showed significantly more severe bacterial spot disease. Application of spent mushroom compost under polyethylene mulch significantly enhanced tomato fruit yield and number of fruits/plant compared to the biofungicide Root Guardian ® , but increased bacterial spot severity compared to Plant Guardian ® . The results of this study indicated that winter cover crops enhance yields of tomato by minimizing disease while reflective polyethylene mulch and spent mushroom compost are conducive to growth and fruit yield in field-grown organic tomato.

No abstract

Weeds and diseases are major biological competitors that pose significant threats to organic production of vegetables in southeastern US during the summer. We evaluated plasticulture as an alternative weed and disease management strategy for open field organic production of bell peppers. The objective of the research was to assess the effects of four colored plastic mulches on soil temperature, moisture, fruit yield and suppression of weeds and diseases on bell pepper. Bell pepper cv ‘King Arthur’ was planted on raised soil beds covered with colored (olive green, black, white and silver) mulch treatments including a control (bare soil). The experimental design was a randomized complete block with four replications. Soil temperature and moisture, disease incidence and severity, and fruit yield were determined. Plant performance (growth and yield) varied with mulch type. The black and olive plastic mulches warmed the soil significantly more than the reflective silver and bare soil. Bell pepper plants across all mulch treatments exhibited susceptibility to bacterial leaf spot (BLS). However, the incidence and severity of BLS varied with mulch type. Plants on reflective silver plastic displayed significant BLS incidence and severity compared to the olive plastic and bare soil. The black, white, and reflective silver plastic mulches significantly increased fruit yields, while the olive mulch and bare soil exhibited poor crop performance. These results suggest that the black and white plastic mulches retain the potential to be used in organic vegetable production in Alabama and the southeastern US.