INTRODUCTION

1. Measuring the Effectiveness of Cover Crop Planting Techniques for Winter Cover Crop Establishment Following Corn in Maryland Kristin A. Fisher, Master’s degree thesis, Hood College  R. Kratochvil, University of Maryland INTRODUCTION METHODS RESULTS – YEAR 2 CONCLUSIONS • Two winter cover cropping seasons: 2007-2008 & 2008-2009 • Two research sites: Beltsville, MD & Poolesville, MD • Two planting dates: Early (before 1 October) & Late (between 20 October and 1 November) • Seedling emergence counts taken weekly after planting • Biomass and nitrogen samples taken mid-winter and early spring • Nitrogen concentration of biomass samples Ten (11 at one location during 2008) seeding techniques (treatments) were replicated three times for each planting date at each location: Poolesville Beltsville • Cover crop planting methods which ensure seed incorporation into the soil (the no-till drill, disked, and Turbo-tilled plots) consistently established the best stands, produced the most biomass and absorbed the most nitrogen regardless of vari-ations in temperature, rainfall, and planting date. • Cover crops perform best when planted early. The plots planted on the early planting date consistently performed better than those planted on the later planting date (late planting date data not shown). • There is a benefit to broadcasting seed as a means of establishing cover crops. This method is highly dependent upon rainfall and mild temperatures for success, but it does provide some nitrogen immobilization over the winter months and therefore provides a small benefit to water quality. • Increasing the seeding rate for broadcasting cover crops without incorporation is warranted. This is based on our observations for the higher rate for both wheat and rye producing biomass and having nitrogen uptake that, at times, was not different from the no-till drill treatments (Fig. 4 and 6). • Wheat and rye within the same treatment performed similarly in most cases. Where there were differences in seedling count maximum, biomass production, or nitrogen uptake, rye always outperformed wheat. Cereals such as wheat (Triticum aestivum L.) and rye (Secale cereale L.) are planted as cover crops on agricultural fields after the harvest of a cash crop. Their purpose is to consume residual soil nitrogen and prevent it from leaching during the winter months. In Maryland, the Department of Agriculture sponsors a Winter Cover Crop Program that pays farmers to plant cover crops as a way to reduce the amount of nitrogen that enters local waterways and ultimately the Chesapeake Bay. In order to be eligible for the program, farmers must use certain planting methods for establishing the cover crops. These include no-till drilling, conventional tillage and drilling, broadcast seed followed by light tillage , aerial seeding, and broadcast seed followed by stalk-chopping (mowing corn stalks). The number of acres planted to winter cover crops has plateaued at approximately 25% of eligible acres despite increases in incentive payments. Planting of cover crops occurs at a time of year when daylight and available labor are limited. Farmers who reside in this watershed where the implementation of agricultural best management practices, such as use of cover crops, will likely receive increased attention in the coming years, wanted to know the benefits of establishing cover crops by broadcasting the seed without any incorporation of the seed into the soil. Figure 5: Seedling germination success by planting technique plus rainfall amount and date at the Poolesville location during fall 2008. BC = Broadcast, NT = no-till drill, SC = stalk-chopped. Figure 7: Seedling germination success by planting technique plus rainfall amount and date at the Beltsville location during fall 2007. BC = Broadcast, NT = no-till drill, SC = stalk-chopped. RESULTS – YEAR 1 Beltsville Poolesville Figure 6: Nitrate absorption by cover crop planting technique for early April 2009 sampling date at Poolesville, MD. BC = Broadcast, NT = no-till drill, SC = stalk-chopped Figure 8: Nitrate absorption by cover crop planting technique for early April 2008 sampling date at Beltsville, MD. BC = Broadcast, NT = no-till drill, SC = stalk-chopped DISCUSSION Year 1 of the study followed a drought which did not break until late in October. This resulted in delayed germination of nearly four weeks for many of the broadcast treatments compared with emergence for the treatments that incorporated seed into the soil (Fig. 1 and 3). The prior corn crop at both sites received a total of 157 kg ha-1. This was a nitrogen rate for an expected corn yield of approximately 8.8 - 9.4 MT ha-1, but the drought resulted in harvest yields of only 6.7 MT ha-1 in Poolesville and 8.4 MT ha-1 in Beltsville. Since both sites received the same nitrogen rate and had no history of manure use, this difference in corn yield between sites probably resulted in more residual nitrogen at Poolesville than at Beltsville. This is reflected in the differences in nitrogen uptake between the two sites (Fig 2 and 4). Generally those treatments that incorporated the seed into the soil had greater nitrogen uptake than the BC treatments without any incorporation. While both the early and late planting date treatments absorbed nitrogen, the early planted cover crops produced the most biomass and absorbed the most nitrogen (data for the late planting date not shown). Year 2 of the study followed a more typical summer and early fall precipitation pattern with rain falling at early planting time. This resulted in relatively quick germination across treatments at Poolesville (Fig. 5). At Beltsville (Fig. 7), BC treatments without incorporation were slower to reach maximum seedling emergence but this delay was only about 10 d compared to nearly three weeks the first year. The preceding corn crop at Poolesville received 157 kg ha-1 nitrogen and yielded 8.4 MT ha-1. This likely resulted in less residual nitrogen than remained in Year 1 at Poolesville. The Beltsville corn received 146 kg ha-1 nitrogen and also yielded 8.4 MT ha-1 which likely removed most of the nitrogen that was supplied. The nitrogen uptake measurements for the cover crop treatments at both locations the second year reflect this (Fig. 6 and 8). RESEARCH OBJECTIVE Figure 1: Seedling germination success by planting technique plus rainfall amount and date at the Poolesville location during fall 2007. BC = Broadcast, NT = no-till drill, SC = stalk-chopped. Figure 3: Seedling germination success by planting technique plus rainfall amount and date at the Beltsville location during fall 2007. BC = Broadcast, NT = no-till drill, SC = stalk-chopped. The objective of this research was to evaluate cover crop establishment and performance using different seeding methods for wheat and rye following corn harvest in Maryland. We compared ten planting methods for stand establishment, biomass production, and nitrogen uptake. While significant research on cover crops has been done in the mid-Atlantic region, a comparative study of cover crop planting techniques has not been performed. The results of this study can be used to support and/or modify current recommendations for planting cereal winter cover crops. ACKNOWLEDGEMENTS Research reported in this document was originally published in a Master’s degree thesis sponsored by the Department of Environmental Biology and submitted to the Graduate School of Hood College in Frederick, Maryland. Special thanks to Dr. Robert Kratochvil from the University of Maryland for serving as thesis advisor for this research and to the Maryland Grain Producers Utilization Board, who provided funding for it. Figure 2: Nitrate absorption by cover crop planting technique for early April 2008 sampling date at Poolesville, MD. BC = Broadcast, NT = no-till drill, SC = stalk-chopped Figure 4: Nitrate absorption by cover crop planting technique for early April 2008 sampling date at Beltsville, MD. BC = Broadcast, NT = no-till drill, SC = stalk-chopped