scholarly journals Use of Crop Rotations, Cover Crops and Green Manures for Disease Suppression in Potato Cropping Systems

Author(s):  
Robert P. Larkin

Crop rotations and the inclusion of cover crops and green manures are primary tools in the sustainable management of soil-borne diseases in crop production systems. Crop rotations can reduce soil-borne disease through three general mechanisms: (1) serving as a break in the host-pathogen cycle; (2) by altering the soil physical, chemical, or biological characteristics to stimulate microbial activity and diversity; or (3) directly inhibiting pathogens through the release of suppressive or toxic compounds or the enhancement of specific antagonists. Brassicas, sudangrass, and related plant types are disease-suppressive crops well-known for their biofumigation potential but also have other effects on soil microbiology that are important in disease suppression. The efficacy of rotations for reducing soil-borne diseases is dependent on several factors, including crop type, rotation length, rotation sequence, and use of the crop (as full-season rotation, cover crop, or green manure). Years of field research with Brassica and non-Brassica rotation crops in potato cropping systems in Maine have documented the efficacy of Brassica green manures for the reduction of multiple soil-borne diseases. However, they have also indicated that these crops can provide disease control even when not incorporated as green manures and that other non-biofumigant crops (such as barley, ryegrass, and buckwheat) can also be effective in disease suppression. In general, all crops provided better disease control when used as green manure vs. as a cover crop, but the addition of a cover crop can improve control provided by most rotation crops. In long-term cropping system trials, rotations incorporating multiple soil health management practices, such as longer rotations, disease-suppressive rotation crops, cover crops, and green manures, and/or organic amendments have resulted in greater yield and microbial activity and fewer disease problems than standard rotations. These results indicate that improved cropping systems may enhance productivity, sustainability, and economic viability.

Plant Disease ◽  
2016 ◽  
Vol 100 (9) ◽  
pp. 1910-1920 ◽  
Author(s):  
J. Himmelstein ◽  
J. E. Maul ◽  
Y. Balci ◽  
K. L. Everts

Fall-planted Vicia villosa or Trifolium incarnatum cover crops, incorporated in spring as a green manure, can suppress Fusarium wilt (Fusarium oxysporum f. sp. niveum) of watermelon. During cover crop growth, termination, and incorporation into the soil, many factors such as arbuscular mycorrhizae colonization, leachate, and soil respiration differ. How these cover-crop-associated factors affect Fusarium wilt suppression is not fully understood. Experiments were conducted to evaluate how leachate, soil respiration, and other green-manure-associated changes affected Fusarium wilt suppression, and to evaluate the efficacy of the biocontrol product Actinovate AG (Streptomyces lydicus WYEC 108). General and specific suppression was examined in the field by assessing the effects of cover crop green manures (V. villosa, T. incarnatum, Secale cereale, and Brassica juncea) on soil respiration, presence of F. oxysporum spp., and arbuscular mycorrhizal colonization of watermelon. Cover crop treatments V. villosa, T. incarnatum, and S. cereale and no cover crop were evaluated both alone and in combination with Actinovate AG in the greenhouse. Additionally, in vitro experiments were conducted to measure the effects of cover crop leachate on the mycelial growth rates of F. oxysporum f. sp. niveum race 1 and Trichoderma harzianum. Soil microbial respiration was significantly elevated in V. villosa and Trifolium incarnatum treatments both preceding and following green manure incorporation, and was significantly negatively correlated with Fusarium wilt, suggesting that microbial activity was higher under the legumes, indicative of general suppression. Parallel to this, in vitro growth rates of F. oxysporum f. sp. niveum and Trichoderma harzianum on V. villosa leachate amended media were 66 and 213% greater, respectively, than on nonamended plates. The F. oxysporum spp. population (based on CFU and not differentiated into formae specialis or races) significantly increased in V. villosa-amended field plots. Additionally, the percentage of watermelon roots colonized by arbuscular mycorrhizae following V. villosa and Trifolium incarnatum green manures was significantly higher than in watermelon following bare ground (58 and 44% higher, respectively). In greenhouse trials where cover crops were amended to soil, Actinovate AG did not consistently reduce Fusarium wilt. Both general and specific disease suppression play a role in reducing Fusarium wilt on watermelon.


2010 ◽  
Vol 28 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Ana Clarissa A Negrini ◽  
Paulo César T de Melo ◽  
Edmilson José Ambrosano ◽  
Rogério Haruo Sakai ◽  
Eliana Aparecida Schammass ◽  
...  

The performance of lettuce in sole and intercropped with green manures was assessed under different establishment times. The lettuce fresh and dry weight, number of leaves per plant, diameter and length of head, and fresh and dry weight of green manure were evaluated. The intercropping design was additive and both cash and cover crops were planted in rows. The experimental design was of randomized complete blocks in split plot scheme, with six replicates. The plots represented the green manure sowing days (0, 20, 40 and 60 before transplanting of lettuce), and the sub-plots were assigned by cropping systems (lettuce in sole crop and intercropped with black oat, cowpea or white lupin). Simultaneous planting in the intercropping did not affect the lettuce performance. However, when the green manures were sown before lettuce, they influenced it in a negative way. Among the green manures, cowpea increased biomass and had a higher negative effect on lettuce performance compared to white lupin, which appeared to produce less competition. The sole crop and the intercropping with simultaneous planting of the green manures resulted in a better lettuce performance.


Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 165
Author(s):  
Robert P. Larkin ◽  
C. Wayne Honeycutt ◽  
Timothy S. Griffin ◽  
O. Modesto Olanya ◽  
Zhongqi He

Cropping systems and management practices that improve soil health may greatly enhance crop productivity. Four different potato cropping systems designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo (SQ) standard rotation, along with a non-rotation (PP) control, were evaluated for their effects on potato crop growth, nutrient, and yield characteristics under both irrigated and non-irrigated (rainfed) conditions in field trials in Maine, USA, from 2004 to 2010. Both cropping system and irrigation significantly (p < 0.05) affected most potato crop parameters associated with growth and yield. All rotations increased tuber yield relative to the non-rotation PP control, and the SI system, which included yearly compost amendments, resulted in overall higher yields and a higher percentage of large-size tubers than all other systems with no irrigation (increases of 14 to 90%). DS, which contained disease-suppressive green manures and cover crops, produced the highest yields overall under irrigation (increases of 11 to 35%). Irrigation increased tuber yields in all cropping systems except SI (average increase of 27–37%). SI also resulted in significant increases in leaf area duration and chlorophyll content (as indicators of photosynthetic potential) and root and shoot biomass relative to other cropping systems, particularly under non-irrigated conditions. SI also resulted in higher shoot and tuber tissue concentrations of N, P, and K, but not most micronutrients. Overall, cropping systems that incorporate management practices such as increased rotation length and the use of cover crops, green manures, reduced tillage, and particularly, organic amendments, can substantially improve potato crop growth and yield. Irrigation also substantially increased growth and yield under normal field conditions in Maine, but SI, with its large organic amendments, was essentially a substitute for irrigation, producing comparable results without irrigation.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 840 ◽  
Author(s):  
Ahmed Laamrani ◽  
Paul R. Voroney ◽  
Aaron A. Berg ◽  
Adam W. Gillespie ◽  
Michael March ◽  
...  

The impacts of tillage practices and crop rotations are fundamental factors influencing changes in the soil carbon, and thus the sustainability of agricultural systems. The objective of this study was to compare soil carbon status and temporal changes in topsoil from different 4 year rotations and tillage treatments (i.e., no-till and conventional tillage). Rotation systems were primarily corn and soy-based and included cereal and alfalfa phases along with red clover cover crops. In 2018, soil samples were collected from a silty-loam topsoil (0–15 cm) from the 36 year long-term experiment site in southern Ontario, Canada. Total carbon (TC) contents of each sample were determined in the laboratory using combustion methods and comparisons were made between treatments using current and archived samples (i.e., 20 year and 9 year change, respectively) for selected crop rotations. Overall, TC concentrations were significantly higher for no-till compared with conventional tillage practices, regardless of the crop rotations employed. With regard to crop rotation, the highest TC concentrations were recorded in corn–corn–oats–barley (CCOB) rotations with red clover cover crop in both cereal phases. TC contents were, in descending order, found in corn–corn–alfalfa–alfalfa (CCAA), corn–corn–soybean–winter wheat (CCSW) with 1 year of seeded red clover, and corn–corn–corn–corn (CCCC). The lowest TC concentrations were observed in the corn–corn–soybean–soybean (CCSS) and corn–corn–oats–barley (CCOB) rotations without use of cover crops, and corn–corn–soybean–winter wheat (CCSW). We found that (i) crop rotation varieties that include two consecutive years of soybean had consistently lower TC concentrations compared with the remaining rotations; (ii) TC for all the investigated plots (no-till and/or tilled) increased over the 9 year and 20 year period; (iii) the no-tilled CCOB rotation with 2 years of cover crop showed the highest increase of TC content over the 20 year change period time; and (iv) interestingly, the no-till continuous corn (CCCC) rotation had higher TC than the soybean–soybean–corn–corn (SSCC) and corn–corn–soybean–winter wheat (CCSW). We concluded that conservation tillage (i.e., no-till) and incorporation of a cover crop into crop rotations had a positive effect in the accumulation of TC topsoil concentrations and could be suitable management practices to promote soil fertility and sustainability in our agricultural soils.


2017 ◽  
Vol 34 (1) ◽  
pp. 62-76 ◽  
Author(s):  
Jason S. Bergtold ◽  
Steven Ramsey ◽  
Lucas Maddy ◽  
Jeffery R. Williams

AbstractOver the past few decades, farmers have increasingly integrated cover crops into their cropping systems. Cover-crop benefits can help a farmer to achieve sustainability or reduce negative environmental externalities, such as soil erosion or chemical runoff. However, the impact on farm economics will likely be the strongest incentive to adopt cover crops. These impacts can include farm profits, cash crop yields or both. This paper provides a review of cover-crop adoption, production, risk and policy considerations from an economic perspective. These dimensions are examined through a review of cover-crop literature. This review was written to provide an overview of cover crops and their impacts on the farm business and the environment, especially with regard to economic considerations. Through increasing knowledge about cover crops, the intent here is to inform producers contemplating adoption and policy makers seeking to encourage adoption.


2010 ◽  
Vol 46 (3) ◽  
pp. 309-325 ◽  
Author(s):  
C. THIERFELDER ◽  
P. C. WALL

SUMMARYConservation agriculture (CA) systems are based on minimal soil disturbance, crop residue retention and crop rotation. Although the capacity of rotations to break pest and disease cycles is generally recognized, other benefits of crop rotations in CA systems are seldom acknowledged and little understood. We monitored different conventional and CA cropping systems over the period from 2005 to 2009 in a multi-seasonal trial in Monze, southern Zambia. Both monocropped maize and different maize rotations including cotton and the green manure cover crop sunnhemp (Crotalaria juncea) were compared under CA conditions, with the aim of elucidating the effects of crop rotations on soil quality, soil moisture relations and maize productivity. Infiltration, a sensitive indicator of soil quality, was significantly lower on conventionally ploughed plots in all cropping seasons compared to CA plots. Higher water infiltration rate led to greater soil moisture content in CA maize treatments seeded after cotton. Earthworm populations, total carbon and aggregate stability were also significantly higher on CA plots. Improvements in soil quality resulted in higher rainfall use efficiency and higher maize grain yield on CA plots especially those in a two- or three-year rotation. In the 2007/08 and 2008/2009 season, highest yields were obtained from direct-seeded maize after sunnhemp, which yielded 74% and 136% more than maize in the conventionally ploughed control treatment with a continuous maize crop. Even in a two-year rotation (maize-cotton), without a legume green manure cover crop, 47% and 38% higher maize yields were recorded compared to maize in the conventionally ploughed control in the two years, respectively. This suggests that there are positive effects from crop rotations even in the absence of disease and pest problems. The overall profitability of each system will, however, depend on markets and prices, which will guide the farmer's decision on which, if any, rotation to choose.


Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 945-952 ◽  
Author(s):  
Nicole M. Viaene ◽  
George S. Abawi

Host suitability for Meloidogyne hapla of six cover crops was tested in the greenhouse. Sudan-grass cv. Trudan 8 and rye (mixture of cultivars) were nonhosts; oat cv. Porter was a poor host; and phacelia cv. Angelia, oilseed radish cv. Renova, and yellow mustard cv. Martigena were maintenance hosts. When incorporated as a green manure before planting of lettuce cv. Mon-tello, sudangrass was the most effective of the cover crops in reducing egg production of M. hapla. Soil amendment with all parts of sudangrass resulted in lower reproduction of M. hapla on lettuce than soil amendment with only roots of sudangrass. Soil incorporation of 2-month-old (or younger) tissues of sudangrass was more effective in reducing nematode reproduction on subsequent lettuce plants than incorporation of 3-month-old tissues. Sudangrass was grown as a cover crop after lettuce for three growing seasons in field microplots and incorporated as a green manure before the first fall frost. Weight of lettuce heads was significantly higher and reproduction of M. hapla was significantly lower in sudangrass-amended microplots compared with those left fallow between lettuce crops, but results varied with year and nematode infestation level.


2016 ◽  
Vol 82 (6) ◽  
pp. 1767-1777 ◽  
Author(s):  
Neiunna L. Reed-Jones ◽  
Sasha Cahn Marine ◽  
Kathryne L. Everts ◽  
Shirley A. Micallef

ABSTRACTCover crops provide several ecosystem services, but their impact on enteric bacterial survival remains unexplored. The influence of cover cropping on foodborne pathogen indicator bacteria was assessed in five cover crop/green manure systems: cereal rye, hairy vetch, crimson clover, hairy vetch-rye and crimson clover-rye mixtures, and bare ground. Cover crop plots were inoculated withEscherichia coliandListeria innocuain the fall of 2013 and 2014 and tilled into the soil in the spring to form green manure. Soil samples were collected and the bacteria enumerated. Time was a factor for all bacterial populations studied in all fields (P< 0.001).E. colilevels declined when soil temperatures dipped to <5°C and were detected only sporadically the following spring.L. innocuadiminished somewhat but persisted, independently of season. In an organic field, the cover crop was a factor forE. coliin year 1 (P= 0.004) and forL. innocuain year 2 (P= 0.011). In year 1,E. colilevels were highest in the rye and hairy vetch-rye plots. In year 2,L. innocualevels were higher in hairy vetch-rye (P= 0.01) and hairy vetch (P= 0.03) plots than in the rye plot. Bacterial populations grew (P< 0.05) or remained the same 4 weeks after green manure incorporation, although initial reductions inL. innocuanumbers were observed after tilling (P< 0.05). Green manure type was a factor only forL. innocuaabundance in a transitional field (P< 0.05). Overall, the impacts of cover crops/green manures on bacterial population dynamics in soil varied, being influenced by bacterial species, time from inoculation, soil temperature, rainfall, and tillage; this reveals the need for long-term studies.


2019 ◽  
Vol 11 (9) ◽  
pp. 73
Author(s):  
João Nacir Colombo ◽  
Mário Puiatti ◽  
Marcelo Rodrigo Krause ◽  
Marília Cecília Bittencourt ◽  
Janiele Cássia Barbosa Vieira ◽  
...  

Although several studies about intercropping green manures with vegetable crops have already been carried out, there are few studies in which the economic analysis was performed. The aim of the present study was to evaluate the economic profitability of the taro and Crotalaria juncea consortium, as well as broccoli, green maize and snow pea grown in succession. The treatments correspond to 10 different cutting dates of the sunn hemp during its intercropping with taro (55, 70, 85, 100, 115, 130, 145, 160, 190 and 220 DAS-days after sowing), plus the monoculture of the taro. Under the legumious cover crop straw were grown in succession: broccoli, green maize and snow pea. The use of Crotalaria juncea in a consortium does not affect the productivity and economic profitability of the taro when cutting up to 130 DAS. The residual effect of Crotalaria juncea grown in consortium with taro increases the economic yield of broccoli when the cutting is performed from 145 DAS. However, it does not affect green maize and snow pea. When the taro is cultivated intercropped with Crotalaria juncea and in succession broccoli, green maize and snow pea are grown, higher yields and economic incomes are obtained by cutting the leguminous green manure up to 130 DAS.


2021 ◽  
Vol 51 (8) ◽  
Author(s):  
Sandra Santana de Lima ◽  
Dérique Biassi ◽  
Cyndi dos Santos Ferreira ◽  
Priscila Silva Matos ◽  
Lucas Vasconcelos Rocha ◽  
...  

ABSTRACT: This study assessed the effect of cover crop biomass on the epigeal fauna of an organic eggplant (Solanum melongena L.) cropping system. A randomized block design was used, with four cover crop treatments: brachiaria, crotalaria, millet, and cocktail (brachiaria, crotalaria and millet). The epigeal faunal indices were determined at each plot. The epigeal fauna of a secondary forest site was also assessed for comparison. Epigeal individuals were collected using pitfall traps at two sampling periods (110 and 180 days after mowing cover crops). Soil samples were collected for determination of physical and chemic properties. 2032 individuals were captured in the first sampling and 3806 individuals in the second. The highest values of wealth in the first collection were observed in the millet and cocktail areas. Cluster analysis showed similarity of epigeal faunal groups between millet and brachiaria plots at the first sampling and between cocktail and crotalaria sites at the second sampling. Co-inertia analysis showed a significant covariance between epigeal fauna at the second sampling and soil properties. The cover crops management had a beneficial influence on the activity, wealth and ecological indexes, in both sampling periods. The positive association observed between epigeal faunal groups and soil physical and chemical properties demonstrates the efficiency of cover crops in improving soil quality in organic cropping systems.


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