Grass and Legume Cover Crop Effects on Dry Matter and Nitrogen Accumulation

Abstract

concentration of the cover crop mixture through biological N fixation and minimizing the potential for short-Careful cover crop management during the spring growth period term N immobilization (Ranells and Wagger, 1997). may allow farmers to maximize dry matter (DM) yield and N accumulation for the subsequent crop. A 2-yr study was conducted to deter-In cool northern climates such as Ontario (Tollenaar mine the effect of grass and legume cover crops on spring DM produc- et al., 1993), Washington (Kuo et al., 1996, 1997, and tion and N accumulation. Each year, cover crops were planted in late Maine (Griffin et al., 2000), rye can produce a substan-August and late September on a loamy, mixed, mesic Humaquept in tial amount of DM as a winter cover crop, generally the Fraser River Delta. Wheat (Triticum aestivum L.), rye (Secale from 2.5 to 5.5 Mg DM ha Ϫ1 . However, the tissue N cereale L.), and ryegrass (Lolium multiflorum L.) were planted in concentration is commonly 10 to 15 g kg Ϫ1 or less, espemonoculture and in mixtures with crimson clover (Trifolium incarnacially after seed head emergence, so the total N accumutum L.). Other treatments included pure stand of crimson clover and lation may be low. Griffin et al. (2000) reported that wheat-hairy vetch (Vicia villosa Roth.) mixture. Cover crop biomass the total DM for rye and rye-vetch mixture ranged was sampled three times in 1995 and four times in 1996 during the from approximately 3.7 to 6.9 Mg DM ha Ϫ1 just before spring growth period. Dry matter accumulation of early planted cover crops increased by 26 to 269% during the spring growth period, ranging incorporation in late May. The total DM for rye and between 0.6 Mg ha Ϫ1 for clover and 10 Mg ha Ϫ1 for wheat, wheat-rye-vetch treatments was similar to that found in more clover, and wheat-vetch treatments. Late-planted cover crops prosouthern locations, including Maryland (Clark et al., duced between 15 and 75% lower DM yield compared with early 1994; Shipley et al., 1992), North Carolina (Ranells and planted cover crops. Nitrogen accumulation increased by 3 to 74 kg Wagger, 1996), and Georgia (McVay et al., 1989), demha Ϫ1 for early planted crops and by 3 to 47 kg ha Ϫ1 for late-planted onstrating that these cover crops are well adapted to a crops. Nitrogen accumulation at final spring sampling ranged from moderately cool growing environment. 44 to 144 kg ha Ϫ1 for early planted crops and from 10 to 99 kg ha Ϫ1 Traditionally, nonlegume cover crops have been alfor late-planted crops. The low C/N ratio of wheat-vetch treatment lowed to grow until the summer crop is planted, often compared with wheat monoculture at final sampling indicated the resulting in residues with wide C/N ratios Ͼ25:1 (Ditsch potential for vetch to increase the N content of the mixture.

Cover Crop Use for Managing Broiler Litter Applied in the Fall

“…In both 2007 and 2008, rye total dry matter yields were lower than those reported in literature (Vaughan and Evanylo, 1999;Odhiambo and Bomke, 2001). In Maryland, Clark et al (1994) reported maximum winter rye biomass as cover crop in the range of 6400 and 7100 kg ha −1 .…”

Evaluating and predicting agricultural management effects under tile drainage using modified APSIM

“…Strock et al (2004) applied 134 kg N/ha of Urea to corn and measured southwestern Minnesota winter rye cover crop biomass of 2.7 Mg/ha in spring of 1999 and 1.0 Mg/ha in spring of 2000 with nitrogen concentration of 2.5% and 2.7%, respectively. Also, Odhiambo and Bomke (2001) and Weinert et al (2002) found N concentration in rye and wheat cover crop of 2.9% to 2.2% for biomass of 2.1 to 3.8 Mg/ha. Therefore, the above ground biomass critical and/or minimum N concentration limits used in APSIM may be too low considering that the terminal crop stage for the wheat was floral initiation.…”

“…Winter cover crops minimize soil nitrate before and after the growing season, when it is most subject to leaching (Eigenberg et al, 2002). Winter wheat and rye have been used as cover crops and the biomass nitrogen contents of the two crops are often similar (Odhiambo and Bomke, 2001;Weinert et al, 2002). In general, management strategies to reduce nitrate loss have only been tested over a few years and limited environmental and management conditions, therefore, quantifying the effects under the variety of expected conditions is difficult.…”

Improving Resilience of Northern Field Crop Systems Using Inter-Seeded Red Clover: A Review

“…Cover crops have been shown to influence nitrogen cycling [11][12][13], reduce soil erosion, water run-off and soil losses during intense rainfall events [14][15][16], increase soil organic matter and soil fertility [17][18][19][20][21], suppress weed growth [22][23][24][25], improve soil structure and water holding capacity [26,27], provide suitable habitat for beneficial predator insects and act as non-host crops for nematodes and other pests in the rotation [28]. Legume cover crops also fix their own nitrogen and contribute to the nitrogen requirements of the subsequent crops [29][30][31][32][33][34][35][36].…”