Interplanting Annual Ryegrass, Wheat, Oat, and Corn to Mitigate Iron Deficiency in Dry Beans

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species did not increase iron (Fe) concentration in dry bean tissues suggesting inefficient utilization of Fe present in the dry bean tissues. In 2009, nitrate-nitrogen (NO3-N) and manganese (Mn) concentration in bean tissue were greater in bean monoculture than in grass intercropped beans. Bean monoculture also had greater soil NO3-N concentrations than grass intercropped treatments. In 2009, grass intercrops reduced dry bean yield \u3e25% compared to bean monoculture. Annual ryegrass was the least competitive of the four annual grass species. This suggests that competition from grasses for nutrients, water, or light may have outweighed benefits accruing from grass intercropping. Additional studies are required to determine the appropriate grass and dry bean densities, as well as the optimum time of grass removal

Can Agricultural Management Induced Changes in Soil Organic Carbon Be Detected Using Mid-Infrared Spectroscopy?

A major limitation to building credible soil carbon sequestration programs is the cost of measuring soil carbon change. Diffuse reflectance spectroscopy (DRS) is considered a viable low-cost alternative to traditional laboratory analysis of soil organic carbon (SOC). While numerous studies have shown that DRS can produce accurate and precise estimates of SOC across landscapes, whether DRS can detect subtle management induced changes in SOC at a given site has not been resolved. Here, we leverage archived soil samples from seven long-term research trials in the U.S. to test this question using mid infrared (MIR) spectroscopy coupled with the USDA-NRCS Kellogg Soil Survey Laboratory MIR spectral library. Overall, MIR-based estimates of SOC%, with samples scanned on a secondary instrument, were excellent with the root mean square error ranging from 0.10 to 0.33% across the seven sites. In all but two instances, the same statistically significant (p \u3c 0.10) management effect was found using both the lab-based SOC% and MIR estimated SOC% data. Despite some additional uncertainty, primarily in the form of bias, these results suggest that large existing MIR spectral libraries can be operationalized in other laboratories for successful carbon monitoring

Bean Yields 2009 and 2010

Data collected in the field in 2009 and 2010. Column headings include the following: 1) Year – year that study was conducted. 2) Bean: Refers to the bean market class used in the intercropping treatment plots including B - for black beans, N for Navy beans, NONE for when beans were not presents in a plot. 3) Rep: refers to replication or block number. 4) Grass: refers to grass species used in the intercropping treatment plot including R (Annual Ryegrass), O (Oats), C (Corn), W (Wheat), and NONE (when grass species was not present in the plot). 5) Bean Yield per sub-sample per plot in Kg

Tissue Results for 2009 and 2010 PLOS

Data collected in the field in 2009 and 2010. Column headings include the following: 1) Year – Year that study was conducted. 2) Stage: Refers to the stage of dry bean development when data was collected including; 2-4 or 8-16 TL (trifoliolate leaf stage). 3) Bean: Refers to the bean market class used in the intercropping treatment plots including B - for black beans, N for Navy beans, NONE for when beans were not presents in a plot. 4) Grass: refers to grass species used in the intercropping treatment plot including R (Annual Ryegrass), O (Oats), C (Corn), W (Wheat), and NONE (when grass species was not present in the plot). 5) Rep: refers to replication or block number. 6) Zn – dry bean tissue zinc concentration in ppm 7) Fe - dry bean tissue iron concentration in ppm 8) Mn - dry bean tissue manganese concentration in ppm 9) Cu - dry bean tissue copper concentration in ppm 10) Mo - dry bean tissue molybdenum concentration in ppm 11) NO - dry bean tissue nitrate nitrogen concentration in ppm

Data from: Interplanting annual ryegrass, wheat, oat, and corn to mitigate iron deficiency in dry beans

This study evaluated whether grass intercropping can be used to alleviate Fe deficiency chlorosis in dry beans (Phaseolus vulgaris L.) grown in high pH, calcareous soils with low organic matter. Field studies were conducted at the University of Wyoming Sustainable Agriculture Research and Extension Center in 2009 and 2010. Black- and navy beans were grown alone or intercropped with annual ryegrass (Lolium multiflorum Lam.), oat (Avena sativa L.), corn (Zea mays L.), or spring wheat (Triticum aestivum L.) in a two-factor factorial strip-plot randomized complete block design. All four grass species increased chlorophyll intensity in dry beans. However, grass species did not increase iron (Fe) concentration in dry bean tissues suggesting inefficient utilization of Fe present in the dry bean tissues. In 2009, nitrate-nitrogen (NO3-N) and manganese (Mn) concentration in bean tissue were greater in bean monoculture than in grass intercropped beans. Bean monoculture also had greater soil NO3-N concentrations than grass intercropped treatments. In 2009, grass intercrops reduced dry bean yield >25% compared to bean monoculture. Annual ryegrass was the least competitive of the four annual grass species. This suggests that competition from grasses for nutrients, water, or light may have outweighed benefits accruing from grass intercropping. Additional studies are required to determine the appropriate grass and dry bean densities, as well as the optimum time of grass removal

Soil Test Results for 2010 PLOS

Data collected in the field in 2010. Column headings include the following: 1) Year – Year that study was conducted. 2) Stage: Refers to the stage of dry bean development when data was collected including; Plant (Planting Stage); 2-4, 4-8, or 8-16 TL (trifoliolate leaf stage); Flower (flowering stage). 3) Bean: Refers to the bean market class used in the intercropping treatment plots including B - for black beans, N for Navy beans, NONE for when beans were not presents in a plot. 4) Grass: refers to grass species used in the intercropping treatment plot including R (Annual Ryegrass), O (Oats), C (Corn), W (Wheat), and NONE (when grass species was not present in the plot). 5) Rep: refers to replication or block number. 5) Salt - Refers to the soluble salt content in ppm. 6) OM - soil organic matter content in LOI percentage 7) Zn - soil zinc concentration in ppm 8) Fe - soil iron concentration in ppm 8) Mn - soil manganese concentration in ppm 9) Cu - soil copper concentration in ppm 10) NO - soil nitrate nitrogen concentration in ppm

Chlorophyll 2009 and 2010 PLOS

Data collected in the field in 2009 and 2010. Column headings include the following: 1) Year – year that study was conducted. 2) Stage: Refers to the stage of dry bean development when data was collected including; 2-4 or 8-16 TL (trifoliolate leaf stage). 3) Rep: refers to replication or block number. 4) Bean: Refers to the bean market class used in the intercropping treatment plots including B - for black beans, N for Navy beans, NONE for when beans were not presents in a plot. 5) Grass: refers to grass species used in the intercropping treatment plot including R (Annual Ryegrass), O (Oats), C (Corn), W (Wheat), and NONE (when grass species was not present in the plot). 6) Chloro – Chlorophyll intensity in SPAD units

Effect of grass species intercrops on bean leaf chlorophyll intensity (SPAD units), bean tissue and soil nutrients (mg kg⁻¹) and dry bean grain yield (tons ha⁻¹) in 2009 and 2010 near Lingle, WY.

†<p>Means within a column and year followed by the same letter are not statistically different (alpha  = 0.05).</p>‡<p>Means without letters were not significantly different from other treatments within a year.</p><p>Effect of grass species intercrops on bean leaf chlorophyll intensity (SPAD units), bean tissue and soil nutrients (mg kg⁻¹) and dry bean grain yield (tons ha⁻¹) in 2009 and 2010 near Lingle, WY.</p

Experimental plot plan for one of the four replicates of the study showing rows of grass species (sub-plots) planted perpendicular to rows of dry beans (main plots).

<p>Experimental plot plan for one of the four replicates of the study showing rows of grass species (sub-plots) planted perpendicular to rows of dry beans (main plots).</p

Picture taken in 2009 showing that beans planted in monoculture appeared more chlorotic than those in grass intercropped plots.

<p>Picture taken in 2009 showing that beans planted in monoculture appeared more chlorotic than those in grass intercropped plots.</p