Organic broccoli production on transition soils: Comparing cover crops, tillage and sidedress N

2009 ◽  
Vol 24 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Daniel L. Schellenberg ◽  
Ronald D. Morse ◽  
Gregory E. Welbaum
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Agricultural Research ◽  
N Uptake ◽  
Soil Microbial Activity ◽  
N Availability ◽  
Ecological Processes ◽  
Sunn Hemp ◽  
N Rates ◽  
Leaf N

AbstractLittle information is available about how farmers in transition to organic practices should manage short- and long-term N fertility. The objectives of this research were (1) to evaluate the leguminous cover crops lablab (Dolichos lablab L.), soybean (Glycine max L.), sunn hemp (Crotalaria juncea L.) and a mixture of sunn hemp and cowpea (Vigna sinensis Endl.) as N sources; (2) to compare N availability and broccoli yield when cover crops were incorporated with conventional tillage (CT) or retained as a surface mulch using no-tillage (NT) practices; and (3) to quantify the amount of supplemental sidedress nitrogen required to maximize the yield of organic broccoli (Brassica oleracea Group Italica) on transition soils. Broccoli was grown during the first year after organic transition in the spring and fall of 2006 at the Kentland Agricultural Research Farm near Blacksburg, VA. Spring (P<0.001) and fall (P<0.001) broccoli yield increased as the rate of sidedress N was increased up to 112 kg N ha−1, and showed a quadratic correlation with leaf N (P=<0.001, R2=0.80 and P=<0.001, R2=0.38, respectively). There was no difference in spring broccoli yield between CT and NT; however, CT produced the highest yield in the fall crop. At low sidedress N rates, leaf N was highest in CT plots, but tillage had no effect on N uptake at high N rates. This indicates that early season and perhaps total plant-available mineralized N was greater in CT than NT; however, potential N deficiency in NT soil may be compensated by sidedress N. Broccoli yield was not affected by leguminous cover crop, even though the quantity of cover crop biomass and N contribution was different among species. This suggests that N availability from leguminous cover crops may be impacted by other ecological processes such as soil microbial activity. This study shows that organic CT and NT growers can maximize broccoli yield in transition soils low in N availability, by using leguminous cover crops in combination with moderate amounts of sidedress N.

scholarly journals Cover Crop Biomass Harvest Influences Cotton Nitrogen Utilization and Productivity

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
F. Ducamp ◽  
F. J. Arriaga ◽  
K. S. Balkcom ◽  
S. A. Prior ◽  
E. van Santen ◽  
...  
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Animal Feed ◽  
N Uptake ◽  
Yield Response ◽  
Cotton Production ◽  
Southeastern Us ◽  
N Concentration ◽  
Winter Cover ◽  
N Rates

There is a potential in the southeastern US to harvest winter cover crops from cotton (Gossypium hirsutumL.) fields for biofuels or animal feed use, but this could impact yields and nitrogen (N) fertilizer response. An experiment was established to examine rye (Secale cerealeL.) residue management (RM) and N rates on cotton productivity. Three RM treatments (no winter cover crop (NC), residue removed (REM) and residue retained (RET)) and four N rates for cotton were studied. Cotton population, leaf and plant N concentration, cotton biomass and N uptake at first square, and cotton biomass production between first square and cutout were higher for RET, followed by REM and NC. However, leaf N concentration at early bloom and N concentration in the cotton biomass between first square and cutout were higher for NC, followed by REM and RET. Seed cotton yield response to N interacted with year and RM, but yields were greater with RET followed by REM both years. These results indicate that a rye cover crop can be beneficial for cotton, especially during hot and dry years. Long-term studies would be required to completely understand the effect of rye residue harvest on cotton production under conservation tillage.

scholarly journals Using the cover crop N calculator for adaptive nitrogen fertilizer management: a proof of concept

2019 ◽  
Vol 35 (5) ◽  
pp. 550-560 ◽  
Author(s):  
Julia W. Gaskin ◽  
Miguel L. Cabrera ◽  
David E. Kissel ◽  
Richard Hitchcock
Keyword(s):  
Soil Moisture ◽  
Cover Crops ◽  
Cover Crop ◽  
Block Design ◽  
Decision Support Tool ◽  
N Fertilizer ◽  
Support Tool ◽  
Sunn Hemp ◽  
N Rates ◽  
On Farm

AbstractLegume cover crops can supply a significant amount of nitrogen (N) for cash crops, which is particularly important for organic farmers. Because N mineralization from cover crop residue depends on the amount of biomass, cover crop quality, as well as environmental conditions such as soil moisture and temperature, predicting the amount of N mineralized and the timing of release has been difficult. We have developed a Cover Crop Nitrogen Calculator based on the N subroutine of the CERES crop model and evaluated the use of the predicted N credits on yields of fall broccoli [Brassica oleracea L. (Italica group)] at a research farm and two working farms. Research farm trials consisted of a cowpea (Vigna unguiculata L. Walp.) cover crop and no cover crop treatments, each at four N rates (0N, 0.5N, 1N and 1.5N, with 1N the target N rate of 112 kg N ha−1 in 2013 and 168 kg N ha−1 in 2014 and 2015) in a randomized complete block design. On-farm trials consisted of a cowpea or sunn hemp (Crotolaria juncea L.) cover crop at four N rates (0N, 0.5N, 1N and 1.5N) and no cover crop treatment at the 1N rate in a completely randomized design. Cover crop biomass and quality (N%, carbohydrates%, cellulose% and lignin%) were measured and used with a 5-yr average soil moisture and soil temperature from a local weather station to predict an N credit. In the cover crop treatments, the N rate was modified by the predicted credit, while the no cover crop treatment received the full N fertilizer rate either as feathermeal (certified organic fields) or as urea (conventional field). At the research farm, broccoli yield increased up to the 0.5N rate, and there was no difference in yield between the no cover 0.5N rate and the cover crop 0.5N rate in 2013, 2014 and 2105. On-farm, we saw an N response in two site-years. In these site-years, there was no difference between the no cover 1N rate and the cover crop 1N rate. At the third site-year, no N response was seen. Overall, our results showed using the cover crop credit predicted by the Calculator did not reduce yields. The use of a decision support tool such as the Calculator may help farmers better manage N fertilizer when cover crops are used, and increase cover crop adoption.

scholarly journals Weed Suppression, Nitrogen Availability, and Cabbage Production Following Sunn Hemp or Sorghum-sudangrass

2021 ◽  
pp. 1-9
Author(s):  
Thierry E. Besançon ◽  
Maggie H. Wasacz ◽  
Joseph R. Heckman
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Weed Suppression ◽  
N Availability ◽  
Weed Species ◽  
Common Lambsquarters ◽  
Dry Biomass ◽  
Sunn Hemp ◽  
Sorghum Sudangrass ◽  
Smooth Pigweed

Cover crops included in a crop rotation can help increase nitrogen (N) availability to subsequent crops, raise soil organic matter, and suppress emergence and growth of various weed species. However, weed suppression by cover crops has mostly been investigated shortly after cover crop termination and not over a longer period spanning into the next cropping season. The effects of sunn hemp (Crotalaria juncea) and sorghum-sudangrass (Sorghum ×drummondi) planted the previous year on N availability before transplanting of late summer cabbage (Brassica oleracea), weed germination and growth, and cabbage yield was examined in field studies conducted in 2018 and 2019 at Pittstown, NJ. Results established that there was little evidence for a functional difference in soil N availability for fall cabbage production because of previous cover crop type. Heavy rainfall events both years may have caused major losses of available N that might otherwise be expected to come from N mineralization of residues of legume cover crop like sunn hemp. During the cover crop season, smooth pigweed (Amaranthus hybridus) and common lambsquarters (Chenopodium album) dry biomass was 77% and 82% lower, respectively, in sorghum-sudangrass compared with sunn hemp plots. The subsequent season following sorghum-sudangrass cover crop, dry biomass of broadleaf weeds was lower by 74% and 56% in June and July, respectively, compared with preceding sunn hemp. Smooth pigweed, common lambsquarters, and hairy galinsoga (Galinsoga quadriradiata) were the weed species most consistently affected by preceding sorghum-sudangrass cover crop with biomass decreased by up to 80%, 78%, and 64%, respectively. Thus, it appears that sorghum-sudangrass can provide suppression of some broadleaf species over a relatively long period and is indicative of sorghum-sudangrass allelopathic activity. On the contrary, density and biomass of grassy weeds as well as commercial yield of transplanted cabbage were unaffected by the preceding cover crop. These results suggest that sorghum-sudangrass cover crop could be integrated to transplanted cole crop rotation for providing weed suppression benefits without altering crop yield in New Jersey organic vegetable cropping systems.

scholarly journals Effects of Cover Crops, Compost, and Vermicompost on Strawberry Yields and Nitrogen Availability in North Carolina

2016 ◽  
Vol 26 (5) ◽  
pp. 604-613 ◽  
Author(s):  
John E. Beck ◽  
Michelle S. Schroeder-Moreno ◽  
Gina E. Fernandez ◽  
Julie M. Grossman ◽  
Nancy G. Creamer
Keyword(s):  
North Carolina ◽  
Pearl Millet ◽  
Cover Crops ◽  
Cover Crop ◽  
Crop Yields ◽  
Pennisetum Glaucum ◽  
Organic Production ◽  
Organic N ◽  
N Availability ◽  
Soil N

Summer cover crop rotations, compost, and vermicompost additions can be important strategies for transition to organic production that can provide various benefits to crop yields, nitrogen (N) availability, and overall soil health, yet are underused in strawberry (Fragaria ×ananassa) production in North Carolina. This study was aimed at evaluating six summer cover crop treatments including pearl millet (Pennisetum glaucum), soybean (Glycine max), cowpea (Vigna unguiculata), pearl millet/soybean combination, pearl millet/cowpea combination, and a no cover crop control, with and without vermicompost additions for their effects on strawberry growth, yields, nutrient uptake, weeds, and soil inorganic nitrate-nitrogen and ammonium-nitrogen in a 2-year field experiment. Compost was additionally applied before seeding cover crops and preplant N fertilizer was reduced by 67% to account for organic N additions. Although all cover crops (with compost) increased soil N levels during strawberry growth compared with the no cover crop treatment, cover crops did not impact strawberry yields in the first year of the study. In the 2nd year, pearl millet cover crop treatments reduced total and marketable strawberry yields, and soybean treatments reduced marketable strawberry yields when compared with the no cover crop treatment, whereas vermicompost additions increased strawberry biomass and yields. Results from this study suggest that vermicompost additions can be important sustainable soil management strategies for transitional and certified organic strawberry production. Summer cover crops integrated with composts can provide considerable soil N, reducing fertilizer needs, but have variable responses on strawberry depending on the specific cover crop species or combination. Moreover, these practices are suitable for both organic and conventional strawberry growers and will benefit from longer-term studies that assess these practices individually and in combination and other benefits in addition to yields.

scholarly journals Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

2001 ◽  
Vol 1 ◽  
pp. 22-29 ◽  
Author(s):  
S. Kuo ◽  
B. Huang ◽  
R. Bembenek
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
N Fertilizer ◽  
N Leaching ◽  
Corn Yield ◽  
N Availability ◽  
Soil N ◽  
Soil N Availability ◽  
N Concentration ◽  
Fertilizer Rates

Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during the high N leaching period for vetch cover crop treatment and for the control without the cover crops. The correlation, however, failed for other cover crops largely because of variable effectiveness of the cover crops in reducing NO3leaching during the 5 years of this study. Further research is needed to determine if relay cover crops planted into standing summer crops is a more appropriate approach than fall seeding in this region to gain sufficient growth of the cover crop by fall. Testing with other main crops that have earlier harvest dates than corn is also needed to further validate the effectiveness of the bicultures to increase soil N availability while protecting the water quality.

scholarly journals Effects of Some Cover Crops on Light Extinction and Weed Coverage in Sunflower Field

2014 ◽  
Vol 47 (2) ◽  
pp. 29-40 ◽  
Author(s):  
S. Hassannejad ◽  
A.R. Mobli
Keyword(s):  
Extinction Coefficient ◽  
Cover Crops ◽  
Cover Crop ◽  
Agricultural Research ◽  
Block Design ◽  
Light Extinction ◽  
Research Station ◽  
Hairy Vetch ◽  
Weed Species ◽  
Weed Cover

Abstract In order to evaluate the effects of some cover crops on extinction coefficient and weed cover percentage in sunflower, a field experiment was conducted based on a randomized complete block design with nine treatments and three replicates at the Agricultural Research Station, Tabriz University of Iran, during growing season 2012-2013. Treatments were triticale, hairy vetch, rapeseed, triticale + hairy vetch, triticale + rapeseed, hairy vetch + rapeseed, application of trifluralin herbicide, and controls (weed infested and weed free without planting cover crop). Result indicated than once established, living mulches can rapidly occupy the open space between the rows of the main crop and use the light that would otherwise be available to weeds. In the all cover crops treatments, the light extinction coefficient was increased and weed cover percentage was reduced. Highest reduction in total weed species was observed in hairy vetch + rapeseed and triticale + rapeseed cover crop 61.92% and 61.43 %, respectively, compared to weed infested, so this treatment was better than trifluralin application. It concluded that cover crops could be considered as integrated strategies for weed sustainable management.

Evaluation of Chemical Termination Options for Cover Crops

2018 ◽  
Vol 32 (3) ◽  
pp. 227-235 ◽  
Author(s):  
Matheus G. Palhano ◽  
Jason K. Norsworthy ◽  
Tom Barber
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Agricultural Research ◽  
Yield Potential ◽  
Crop Acreage ◽  
Potential Cost ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Legume Cover Crops ◽  
And Control

AbstractCover crop acreage has substantially increased over the last few years due to the intent of growers to capitalize on federal conservation payments and incorporate sustainable practices into agricultural systems. Despite all the known benefits, widespread adoption of cover crops still remains limited due to potential cost and management requirements. Cover crop termination is crucial, because a poorly controlled cover crop can become a weed and lessen the yield potential of the current cash crop. A field study was conducted in fall 2015 and 2016 at the Arkansas Agricultural Research and Extension Center in Fayetteville to evaluate preplant herbicide options for terminating cover crops. Glyphosate-containing treatments controlled 97% to 100% of cereal rye and wheat, but glyphosate alone controlled less than 57% of legume cover crops. The most effective way to control hairy vetch, Austrian winterpea, and crimson clover with glyphosate resulted from mixtures of glyphosate with glufosinate, 2,4-D, and dicamba. Higher rates of auxin herbicides improved control in these mixtures. Glufosinate alone or in mixture controlled legume cover crops 81% or more. Paraquat plus metribuzin was effective in terminating both cereal and legume cover crops, with control of cereal cover crops ranging from 87% to 97% and control of legumes ranging from 90% to 96%. None of these herbicides or mixtures adequately controlled rapeseed.

Strategies to terminate summer cover crops for weed management in no-tillage vegetable production in southeast Brazil

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Roberto Botelho Ferraz Branco ◽  
Fernando de Carvalho ◽  
João Paulo de Oliveira ◽  
Pedro Luis da Costa Alves
Keyword(s):  
Pearl Millet ◽  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Weed Suppression ◽  
No Tillage ◽  
Weed Biomass ◽  
Jack Bean ◽  
Organic Mulch ◽  
Sunn Hemp

Abstract Cover crop residue left on the soil surface as organic mulch in no-tillage crop production provides several environmental benefits, including weed suppression. Thus, many farmers who use cover crops attempt to reduce the use of agricultural inputs, especially herbicides. Therefore, our objectives were to study the potential of different cover crop species to suppress weeds and produce an in situ organic mulch, and evaluate the effect of the organic mulch with and without spraying glyphosate on weed suppression for vegetable (tomato (Solanum lycopersicum L. and broccoli (Brassica oleracea L. var. botrytis) growth and yield. Five cover crop treatments (sunn hemp (Crotalaria juncea L.), jack bean [Canavalia ensiformis (L.) DC.], pearl millet [Pennisetum glaucum (L.) R. Br.], grain sorghum [Sorghum bicolor (L.) Moench ssp. bicolor] and a no-cover crop (control)) were used in the main plots; and spraying or no spraying glyphosate on the flattened cover crop in the sub plots of split-plot experimental design. Organic mulch from pearl millet, sorghum and sunn hemp resulted in lower weed biomass during the early season of both tomato and broccoli than jack bean and no-cover crop (control). Spraying glyphosate after roller crimping reduced weed biomass by 103 g m−2 and 20 g m−2 by 45 and 60 days after transplanting (DAT) of tomato, respectively and resulted in a better tomato yield compared to non spraying. Glyphosate reduced weed biomass by 110 g m−2 in the early season of broccoli (30 DAT), but did not affect yield. Terminating high biomass cover crops with a roller crimper is a promising technique for weed management in vegetable crops, which has the potential to reduce or even eliminate the need for herbicide.

scholarly journals Detecting Cover Crop End-Of-Season Using VENµS and Sentinel-2 Satellite Imagery

2020 ◽  
Vol 12 (21) ◽  
pp. 3524
Author(s):  
Feng Gao ◽  
Martha C. Anderson ◽  
W. Dean Hively
Keyword(s):  
Remote Sensing ◽  
Time Series ◽  
Cover Crops ◽  
Cover Crop ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Agricultural Research ◽  
Agricultural Landscapes ◽  
Absolute Difference ◽  
Sentinel 2

Cover crops are planted during the off-season to protect the soil and improve watershed management. The ability to map cover crop termination dates over agricultural landscapes is essential for quantifying conservation practice implementation, and enabling estimation of biomass accumulation during the active cover period. Remote sensing detection of end-of-season (termination) for cover crops has been limited by the lack of high spatial and temporal resolution observations and methods. In this paper, a new within-season termination (WIST) algorithm was developed to map cover crop termination dates using the Vegetation and Environment monitoring New Micro Satellite (VENµS) imagery (5 m, 2 days revisit). The WIST algorithm first detects the downward trend (senescent period) in the Normalized Difference Vegetation Index (NDVI) time-series and then refines the estimate to the two dates with the most rapid rate of decrease in NDVI during the senescent period. The WIST algorithm was assessed using farm operation records for experimental fields at the Beltsville Agricultural Research Center (BARC). The crop termination dates extracted from VENµS and Sentinel-2 time-series in 2019 and 2020 were compared to the recorded termination operation dates. The results show that the termination dates detected from the VENµS time-series (aggregated to 10 m) agree with the recorded harvest dates with a mean absolute difference of 2 days and uncertainty of 4 days. The operational Sentinel-2 time-series (10 m, 4–5 days revisit) also detected termination dates at BARC but had 7% missing and 10% false detections due to less frequent temporal observations. Near-real-time simulation using the VENµS time-series shows that the average lag times of termination detection are about 4 days for VENµS and 8 days for Sentinel-2, not including satellite data latency. The study demonstrates the potential for operational mapping of cover crop termination using high temporal and spatial resolution remote sensing data.

scholarly journals Drainage N Loads Under Climate Change with Winter Rye Cover Crop in a Northern Mississippi River Basin Corn-Soybean Rotation

2020 ◽  
Vol 12 (18) ◽  
pp. 7630
Author(s):  
Robert Malone ◽  
Jurgen Garbrecht ◽  
Phillip Busteed ◽  
Jerry Hatfield ◽  
Dennis Todey ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Crop Yield ◽  
Mississippi River ◽  
Cover Crops ◽  
Cover Crop ◽  
General Circulation ◽  
N Uptake ◽  
Winter Rye ◽  
Mississippi River Basin

To help reduce future N loads entering the Gulf of Mexico from the Mississippi River 45%, Iowa set the goal of reducing non-point source N loads 41%. Studies show that implementing winter rye cover crops into agricultural systems reduces N loads from subsurface drainage, but its effectiveness in the Mississippi River Basin under expected climate change is uncertain. We used the field-tested Root Zone Water Quality Model (RZWQM) to estimate drainage N loads, crop yield, and rye growth in central Iowa corn-soybean rotations. RZWQM scenarios included baseline (BL) observed weather (1991–2011) and ambient CO2 with cover crop and no cover crop treatments (BL_CC and BL_NCC). Scenarios also included projected future temperature and precipitation change (2065–2085) from six general circulation models (GCMs) and elevated CO2 with cover crop and no cover crop treatments (CC and NCC). Average annual drainage N loads under NCC, BL_NCC, CC and BL_CC were 63.6, 47.5, 17.0, and 18.9 kg N ha−1. Winter rye cover crop was more effective at reducing drainage N losses under climate change than under baseline conditions (73 and 60% for future and baseline climate), mostly because the projected temperatures and atmospheric CO2 resulted in greater rye growth and crop N uptake. Annual CC drainage N loads were reduced compared with BL_NCC more than the targeted 41% for 18 to 20 years of the 21-year simulation, depending on the GCM. Under projected climate change, average annual simulated crop yield differences between scenarios with and without winter rye were approximately 0.1 Mg ha−1. These results suggest that implementing winter rye cover crop in a corn-soybean rotation effectively addresses the goal of drainage N load reduction under climate change in a northern Mississippi River Basin agricultural system without affecting cash crop production.

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