What’s Cropping Up? Volume 30, No. 3 – May/June 2020

The full version of What’s Cropping Up? Volume 30 No. 3 is available as a downloadable PDF on issuu. This issue includes links to COVID-19 resources on the back page. And as always, individual articles are available below:

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Meadow Fescue-Alfalfa Mixtures in Northern New York

J.H. Cherney1 and D.J.R. Cherney2
1Soil and Crop Sciences Section, School of Integrative Plant Science; 2Animal Science Department; Cornell University

Over 90% of the alfalfa acreage in northern NY is seeded with a perennial grass. Meadow fescue is becoming increasingly popular for mixtures with alfalfa in New York. Most meadow fescue varieties were developed in northern Europe or at higher elevations in southern Europe. Meadow fescues are very winter hardy and tolerant of wet soils, they have been popular for both grazing and hay in Canada for decades. They have also been shown in NY and WI trials to be higher in fiber digestibility than other grasses more commonly used in mixture with alfalfa in the northern USA.

One concern in the Northeast has been the seeding rate for meadow fescue with alfalfa. This grass is very aggressive when grown with alfalfa, particularly if soil conditions are not optimal for alfalfa production. We evaluated one diploid (SW Minto) and one tetraploid (Tetrax) meadow fescue at 5 seeding rates with either a reduced-lignin alfalfa (HarvXtra) or a conventional high-quality alfalfa (Hi-Gest 360).

Procedure

In May, 2018, we planted field trials on farms near Copenhagen in Jefferson County, NY (Site 1) and near Lowville in Lewis County, NY (Site 2). HarvXtra and Hi-Gest 360 were seeded at approximately 15 lbs/a, with the same number of pure live seeds per sq. ft. for both alfalfa varieties. Tetrax meadow fescue was seeded at 0.5, 1, 2, 3, and 4 lbs/a, with the same number of pure live seeds per sq. ft. for SW Minto. Tetraploid meadow fescue seed is up to three times greater in weight per seed compared to most diploid varieties.

Plots at both sites were mowed to control weeds during the seeding year, and no data was collected. In 2019, three photographs were taken per plot (covering >70% of the plot area) prior to each harvest and were visually evaluated for grass percentage. Site 1 was harvested four times in 2019, on 6 June, 10 July, 12 August, and 18 September. Site 2 was harvested three times on 31 May, 15 July, and 14 August. At each harvest, forage quality and dry matter samples were collected prior to harvest, and forage quality samples were separated into alfalfa and grass components for laboratory analysis.

Forage Yield

Dry matter yield for Site 1 averaged 5.1 dry tons/acre and was 67% greater than Site 2. Site 2 had a soil pH of 6.4 at spring harvest in 2019 and had been adequately fertilized, but alfalfa never looked reasonably healthy and had a stunted appearance throughout the season. There was insufficient regrowth to justify a fourth harvest at Site 2. Yield at both sites was primarily attributed to spring growth. Site 1 yield distribution was 41%, 29%, 18%, and 12% for four cuts, while Site 2 yield distribution was 61%, 28%, and 10% for three cuts. Yield at both sites was influenced by grass seeding rate (Fig. 1).

Graph 1
Fig. 1. Yield of alfalfa-meadow fescue as related to grass seeding rate.

Grass Percentage in Mixtures

Struggling alfalfa resulted in very high grass percentages at Site 2 (Fig. 2). Although alfalfa was normal in appearance at Site 1, grass percentage was also high for the year after seeding. SW Minto was considerably higher in grass percentage of mixtures than Tetrax at both sites (Fig. 3). Grass percentage consistently agreed with grass seeding rate, but plots with the 0.5 lb/acre grass seeding rate were less uniform than at higher seeding rates. Visual estimation of a majority of the plot area provided more consistent results than calculating a grass percentage estimation based on a small, separated sample of alfalfa-grass that may or may not be representative of the entire plot.

Graph 2
Fig. 2. Grass percentage in mixtures for Tetrax meadow fescue in 2019 at two sites, averaged over harvests, weighted for dry matter yield.
Graph 3
Fig. 3. Grass percentage in mixtures in 2019 for two meadow fescues averaged over two sites, and averaged over harvests, weighted for dry matter yield.

Grass Quality

Grass crude protein (CP) was related to the proportion of alfalfa in the mixture, as alfalfa provides grass with nitrogen (Fig. 4). Grass quality was very similar between sites. Across sites and harvests, Tetrax averaged 51% NDF, while SW Minto averaged 55%. Tetrax averaged 2.5% greater fiber digestibility (NDFD48h) than SW Minto across sites. NDF, ADF, and lignin tended to increase with increased grass seeding rate, while in vitro digestibility and NDFD decreased with increasing grass seeding rate. Grasses were harvested prior to heading, so we lack relative maturity information, however, these two grasses had the same spring heading date in Ithaca, NY in 2019. Meadow fescue averaged 82% NDFD over variety, site and harvest, while alfalfa averaged 56%.

Graph 4
Fig. 4. Crude protein in meadow fescue as influenced by grass seeding rate in alfalfa-grass mixtures in 2019. Average of two meadow fescue varieties and two sites. Harvests were also averaged, weighted for yield.

Alfalfa Quality

With less than ideal sites for alfalfa production, grass dominated stands at all but the lowest grass seeding rates. Typical forage quality differences between reduced-lignin alfalfa and conventional alfalfa were not observed at these sites. HarvXtra was significantly lower in lignin (but only 2.7% lower) than Hi-Gest 360 at Site 2, and varieties did not differ for lignin at Site 1. HarvXtra had 4.2% greater NDFD than Hi-Gest 360 at Site 1, while alfalfa varieties did not differ for NDFD at Site 2. Alfalfa composition was not affected by grass seeding rate.

Harvesting grass with reasonably good forage quality in mixtures in the spring in NY often results in alfalfa harvested at relatively immature stages. For example, mixtures were harvested on June 6, 2019 at Site 1, and alfalfa averaged 30% NDF, while grass averaged 58% NDF. A common rule of thumb for alfalfa is harvesting in the spring at approximately 40% NDF after accumulating 750 growing degree days (GDDbase41F). The two sites reached 750 GDD on June 15 and June 17.

Summary

Meadow fescue is well adapted to colder environments and to somewhat marginal soils. Meadow fescue also is generally high in fiber digestibility compared to other cool-season grasses typically sown with alfalfa in the Northeast. It is very competitive with alfalfa under such conditions. If the goal of a mixed seeding for dairy forage is to produce a stand with 20-30% grass on soil not ideally suited to alfalfa, meadow fescue seeding rate should probably not exceed 1 lb/acre. While seeding rates can be controlled, climatic conditions cannot. Grass percentage in alfalfa-grass mixtures can be greatly affected by soil moisture, particularly for the first month after seeding. Shallow-rooted young grass seedlings are much more susceptible to drought than alfalfa seedlings.

Reduced-lignin alfalfa may not perform as well on more marginal soils, as it generally does on good alfalfa soils. In these trials and other studies conducted in NY, Tetrax meadow fescue has been less aggressive with alfalfa than most meadow fescues evaluated and is often higher in fiber digestibility. There are over 120 meadow fescue varieties certified for sale in Europe; few are currently sold in North America. Optimum seeding rate for meadow fescue with alfalfa may vary for different cultivars and for different regions in the Northeast; more research on meadow fescue varieties is warranted.

This research was supported by the Northern New York Agricultural Development Program.

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What’s Cropping Up? Volume 29 Number 3 – July/August 2019

Nitrogen Management for Forage Winter Cereals in New York

Sarah E. Lyonsa, Quirine M. Ketteringsa, Shona Orta, Gregory S. Godwina, Sheryl N. Swinka, Karl J. Czymmeka,b, Debbie J. Cherneyc, Jerome H. Cherneyd, John J. Meisingere, and Tom Kilcera,f

a Nutrient Management Spear Program, Department of Animal Science, Cornell University, Ithaca, NY, b PRODAIRY, Department of Animal Science, Cornell University, Ithaca, NY, cDepartment of Animal Science, Cornell University, Ithaca, NY, dSoil and Crop Sciences Section of the School of Integrative Plant Science, Cornell University, Ithaca, NY, eUSDA-ARS Beltsville Agricultural Research Center, Beltsville, MD, fAdvanced Agricultural Systems, LLC, Kinderhook, NY

Introduction

Forage double-cropping, or growing two forage crops in a single growing season, can be a beneficial practice for dairy farmers in New York. Double-cropping corn silage with forage winter cereals, such as triticale, cereal rye, or winter wheat, can add additional spring yield on top of numerous environmental benefits including preventing soil erosion, nutrient recycling, and increased soil organic matter over time – which all promote increased soil health. Winter cereals intended for forage harvest require nitrogen (N) management to reach optimum yield and forage quality. This study was aimed at identifying field and management characteristics that can estimate yield and N needs for winter cereals harvested for forage in the spring.

Field Research

A state-wide study with 62 on-farm trials investigated the spring N needs of forage winter cereals across New York from 2013 to 2016. Each trial had five rates of N (0, 30, 60, 90, and 120 lbs N/acre) applied to farmer-managed forage triticale, cereal rye, or winter wheat at green-up in the spring to determine the most economic rate of N (MERN). All forages were harvested at the flag-leaf stage in May each year. Soil samples were taken at green-up before fertilizer was applied. Farmers supplied information about management practices and field characteristics, such as past manure applications, planting date, and soil drainage. This information, in addition to soil fertility analysis results, was used to develop a decision tree model for predicting MERN classification.

Results

About one-third of the trials did not require additional N (MERN = 0), while the remainder responded to N and most required between 60 and 90 lbs N/acre (Figure 1). Yields at the MERN across trials ranged from 0.4 to 3.0 tons DM/acre (1.8 tons DM/acre average). Yield could not be accurately predicted based on information gathered, but the lower-yielding sites (< 1.0 tons of DM/acre) tended to be poorly or somewhat poorly drained and not have a recent manure history.

Farmer-reported soil drainage, manure history, and planting date were the most important predictors of the MERN (Figure 2). Most of the winter cereals grown on fields that were described as well-drained by the farmers did not require additional N at green-up. For the fields reported as somewhat poorly- or poorly-drained, 60 to 90 lbs N/acre were required if the field had not received manure the previous fall. If manure had been applied recently, 60 to 90 lbs N/acre were required for stands that were planted after October 1 versus 0 lbs N/acre if planting had taken place before October 1.

Forage winter cereal most economic rates of N (MERN) and yield at the MERN
Figure 1. Forage winter cereal most economic rates of N (MERN) and yield at the MERN for 62 N-rate trials in New York from 2013 to 2016. Fertilizer N was applied at spring green-up and forage was harvested at the flag-leaf stag in May.
Decision tree for forage winter cereal most economic rate of N (MERN) at spring green-up
Figure 2. Decision tree for forage winter cereal most economic rate of N (MERN) at spring green-up. If the indicated site or history factor in the blue box is true, move to the left branch in the tree; if false, move to the right branch. The predicted MERN is listed in the red boxes. Recent manure history refers to manure applied within the last year (either spring or fall). This decision tree correctly predicted MERN classifications for 78% of the trials included.
Forage winter cereal crude protein as impacted by N rate applied at spring green-up
Figure 3. Forage winter cereal crude protein as impacted by N rate applied at spring green-up for 62 trials in New York from 2013 to 2016. Forage was harvested at the flag-leaf stage in May.

Most forage quality parameters were not impacted by N rate. Neutral detergent fiber (NDF) at the MERN ranged from 42 to 60% of DM (52% average), in vitro true digestibility (IVTD) at the MERN ranged from 81 to 94% of DM (88% average), and NDFD digestibility (48-hour fermentation) at the MERN ranged from 67 to 84% of NDF (78% average). However, crude protein (CP) increased with N rate for most trials, even those with MERNs of 0. Crude protein averaged 13% of DM for the 0 lbs N/acre treatment and 20% of DM for the 120 lbs N/acre treatment (Figure 3). On average, CP increases by 1% for every 15-20 lbs of N applied. These findings suggest that additional N beyond the MERN can increase the CP levels of the forage while not impacting other forage quality parameters.

Conclusions and Implications

Results from this study emphasize the importance of growing conditions for optimum forage winter cereal performance. In fields that have poor drainage and lack recent manure histories, forage winter-cereals may not yield well and will likely require additional N inputs, while fields with well-drained soil conditions and better soil fertility will support higher yields and better forage quality without needing additional N in the spring. Planting date is also a critical management consideration. Planting late in the fall (after October 1 in this study), may result in lower yields (see also Lyons et al., 2018a). Timely planting (before October 1) in fields with good soil fertility and/or recent manure histories more often resulted in MERNs for N at green-up of 0 lbs N/acre, which would save farmers time and costs in the spring. Nitrogen management at green-up did not greatly affect forage quality except for CP, which increased with N addition even if the additional N did not increase spring yield.

Additional Resources

  • Lyons, S.E., Q.M. Ketterings, G.S. Godwin, J.H. Cherney, K.J. Czymmek, and T. Kilcer. 2018a. Spring N management is important for triticale forage performance regardless of fall management. What’s Cropping Up? 28(2): 34-35.
  • Lyons, S.E., Q.M. Ketterings, G.S. Godwin, K.J. Czymmek, S.N. Swink, and T. Kilcer. 2018b. Soil nitrate at harvest of forage winter cereals is related to yield and nitrogen application at green-up. What’s Cropping Up? 28(2): 32-33.

Acknowledgements

Cornell, Nutrient Management Spear Program, and Pro-Dairy logosThis work was supported by Federal Formula Funds, and grants from the Northern New York Agricultural Development Program (NNYADP), the USDA-NRCS, and Northeast Sustainable Agriculture Research and Education (NESARE). We would also like to thank participatory farmers and farm advisors for assisting with the trials, including Cornell Cooperative Extension educators, consultants, NRCS staff, and SWCD staff. For questions about these results, contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.

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Best Timing of Harvest for Brown Midrib Forage Sorghum Yield, Nutritive Value, and Ration Performance

Sarah E. Lyonsa, Quirine M. Ketteringsa, Greg Godwina, Debbie J. Cherneyb, Jerome H. Cherneyc, Michael E. Van Amburghb, John J. Meisingerd, and Tom F. Kilcere

 a Nutrient Management Spear Program, Department of Animal Science, Cornell University, Ithaca, NY, b Department of Animal Science, Cornell University, Ithaca, NY, c Soil and Crop Sciences Section of the School of Integrative Plant Science, Cornell University, Ithaca, NY, d USDA-ARS Beltsville Agricultural Research Center, Beltsville, MD, and e Advanced Agricultural Systems, LLC, Kinderhook, NY

Introduction

Forage sorghum is a drought and heat tolerant warm-season grass that can be used for silage on dairy farms. Since it requires a soil temperature of at least 60°F for planting, the recommended planting time for New York is early June, unlike corn which is usually planted earlier in the spring. This would allow time for a forage winter cereal harvest in mid- to late-May prior to sorghum planting. Forage sorghum also has comparable forage quality to corn silage for most parameters except for starch, which is typically lower in forage sorghum. The main question for this research was: can forage sorghum be harvested in time for establishment of a fall cover crop or winter cereal double crop in New York? To answer this question, we conducted seven trials in central New York from 2014 through 2017 to evaluate the impact of harvesting at the boot, flower, and milk growth stages versus the traditional soft dough stage on the yield and forage quality of a brown midrib (BMR) forage sorghum variety.

Trial Set-Up

The seven trials were planted between early June and early July on two Cornell research farms in central New York. The sorghum was planted at a 1-inch seeding depth and 15-inch row spacing (15 lbs/acre seeding rate). Two N-rates as urea treated with Agrotain® (Koch Agronomic Services, LLC, Wichita, KS) were broadcast at planting (100 and 200 lbs N/acre) with the goal of having a non-N limiting scenario for these sites. Alta Seeds AF7102 (Alta Seeds, Irving, TX) was used for all trials. Forage sorghum was harvested at the boot, flower, milk, and soft dough stages. Harvest was done using a 4-inch cutting height. Measurements included dry matter (DM) yield and forage quality, including total digestible nutrients (TDN), neutral detergent fiber (NDF) analyzed on an organic matter basis with amylase, 30 hour NDF digestibility (NDFD30), non-fiber carbohydrates (NFC), acid detergent fiber (ADF), dry matter (DM), crude protein (CP), and starch content. Forage quality parameters were entered into the Cornell Net Carbohydrate and Protein System (CNCPS) version 6.55, a ration formulation software, for predicting how sorghum harvested at various growth stages would perform in a typical dairy total mixed ration (TMR) compared to corn silage. Forage sorghum, at each of the different growth stages, was substituted for 0, 25, 50, 75, and 100% of the corn silage fraction of the diet, and metabolizable energy (ME) allowable milk and metabolizable protein (MP) allowable milk were predicted.

Results

Timing of forage sorghum harvest impacted both yield and forage quality. Yield did not increase beyond the flower stage for four trials or beyond the milk stage for one trial. For two trials yield continued to increase until the soft dough stage. Averaged across all trials, yield increased from 4.8 tons DM/acre at the boot stage, to 6.0 tons DM/acre at the flower stage, and 6.8 and 7.1 tons DM/acre at the milk and soft dough stages, respectively (Figure 1). These results suggest that, in most cases, forage sorghum can be harvested at the flower or milk stage without losing a substantial amount of yield. With later harvests forage quality parameters of DM, starch, and NFC were increased while CP, NDF, and NDFD30 were decreased.

Graph of summary of yield and forage quality of BMR brachytic dwarf forage sorghum
Figure 1: Summary of yield and forage quality of BMR brachytic dwarf forage sorghum as impacted by growth stage at harvest. These are averages of seven trials in central New York from 2014-2017. Quality parameters include total digestible nutrients (TDN), neutral detergent fiber (NDF) analyzed on an organic matter basis with amylase, 30 hour NDF digestibility (NDFD30), non-fiber carbohydrates (NFC), acid detergent fiber (ADF), dry matter (DM), crude protein (CP), and starch.

Without adjusting for DM intake, 100% inclusion of forage sorghum harvested at the soft dough stage resulted in predicted ME allowable milk (90 lbs) that was similar to the 100% corn silage TMR (92 lbs) across sorghum inclusion amounts (Fig. 2A). The lower starch content of less mature sorghum resulted in reduced ME allowable milk at greater inclusion in the diet, averaging 87, 88, and 89 lbs for 100% inclusion of sorghum at the boot, flower, and milk stages, respectively. Predicted MP allowable milk for all sorghum growth stages was similar to that of corn silage (Fig. 2B).

Graph of metabolizable energy allowable milk and metabolizable protein allowable milk of forage sorghum
Figure 2: Metabolizable energy (ME) allowable milk (A) and metabolizable protein (MP) allowable milk (B) of BMR brachytic dwarf forage sorghum predicted with the Cornell Net Carbohydrate and Protein System (CNCPS) version 6.55. Harvest took place at four growth stages, and sorghum was substituted for different percentages of corn silage in a typical dairy total mixed ration. Values are averages of seven trials in central New York from 2014 to 2017.

Conclusions and Implications

Forage sorghum can be a good alternative to corn silage in double-cropping rotations with winter cereals grown for forage in New York. The BMR forage sorghum in this study could be harvested as early as the late-flower to early-milk growth stage without losing significant amounts of yield. However, early harvesting did affect forage quality, resulting in greater NDFD30, NDF, ADF, and CP, and less NFC, starch, and DM. Forage sorghum could replace corn silage in a dairy TMR but energy supplements are needed if sorghum is harvested before the soft dough stage due to a lower starch content at the earlier harvest dates. Additional forage may also be needed in a sorghum-based TMR due to changes in fiber digestibility at different growth stages. The higher moisture content of less mature sorghum may also call for adjustments in chop length and/or silage additives, such as inoculants, for proper fermentation.

Additional Resource

Lyons, S., Q.M. Ketterings, G. Godwin, D.J. Cherney, J.H. Cherney, J.J. Meisinger, and T.F. Kilcer (2019). Nitrogen Management of Brown Midrib Forage Sorghum in New York. What’s Cropping Up? 29(1):1-3.

Acknowledgements

Cornell University logo, Nutrient Management Spear Program logo, and Pro-Dairy logoThis work was supported by Federal Formula Funds, and grants from the Northern New York Agricultural Development Program (NNYADP), New York Farm Viability Institute (NYFVI), and Northeast Sustainable Agriculture Research and Education (NESARE). For questions about these results, contact Quirine M. Ketterings at 607-255-3061 or qmk2@cornell.edu, and/or visit the Cornell Nutrient Management Spear Program website at: http://nmsp.cals.cornell.edu/.

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What’s Cropping Up? Volume 29, Number 2 – March/April 2019