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730
Influence of mixed cropping of corn and soybean with different seeding rates on forage yield, quality and nutrient yield grown under organic condition

Wednesday, July 20, 2016: 2:30 PM
251 C (Salt Palace Convention Center)
Ishwary P Acharya , Dairy Science Department, South Dakota State University, Brookings, SD
Xingyou Gu , Deparment of Plant Science, South Dakota State University, Brookings, SD
David P Casper , Dairy and Food Science Department, South Dakota State University, Brookings, SD
Abstract Text:

A field plot study was laid out using a randomized complete block design with three replicates to evaluate two organic corn hybrids [MC 5300 (N) and MasterGraze (MG)] with two soybeans [Viking 2265 (R) and Vining (V)] at four seeding rates (R1 = 65:35; R2 = 55:45; R3 = 45:55, and R4 = 35:65 of corn and soybean) in terms of forage yield, nutrient yields and quality. Forage was hand harvested 101 d (MG corn with both soybeans) and 116 d (N corn with both soybeans) after planting during 2015 season, inoculated, packed into buckets, weighed, and ensiled for 90 d.  Buckets were then re-weighed, opened, and forage samples collected and analyzed for nutrient composition. The main effect of corn for dry matter yield (DMY) was greater (P < 0.05) for N compared to MG (27.73 and 19.90 T/ha for N and MG respectively), while main effect of soybean for DMY was similar (P > 0.05, 23.77 and 23.86 T/ha for R and V respectively). Main effect of seeding rate on DMY was higher (P < 0.05) for R1 and R2 compared to R3 and R4 (25.38, 24.48, 21.81 and 23.59 T/ha for R1, R2, R3 and R4 respectively). Yields of digestible dry matter (DDM; 19.55 and 13.67 T/ha) and CP (2.40 and 2.12 T/ha) were greater (P < 0.05) for N corn compared to MG corn, similar (P > 0.05) for both soybean ( DDM; 16.65 and 16.57 T/ha and CP;  2.33 and 2.19T/ha for R and V respectively) and higher  (P< 0.05) DDM for R1 and R2 compared to R3 and R4 (17.70, 17.08,15.13 and 16.54 T/ha for R1, R2, R3, and R4 respectively). Yield of starch (7.78 and 2.45 T/ha for N and MG) and 30 h NDF digestibility (NDFD30; 44.47 and 52.49 % for N and MG) for main effect of corn were different (P < 0.05) while similar (P > 0.05) for main effect of soybean (starch yield; 5.25 and4.98 T/ha; NDFD30; 48.58 and 48.38% for R and V respectively). The combination of N corn either with R or V soybean at the ratio of R1 or R2 resulted in the greatest yield of DM, DDM and Starch. Forage blend produced through mixed cropping of corn and soybeans holds a great potential for increasing the forage and nutrient yields to meet the nutrient requirements of lactating dairy cows.

Keywords: corn, forage, soybean