Effect of planting density on nutritional quality of green-chopped corn for silage

Abstract

The objective of this on-farm study was to determine the effect of corn planting density on the nutritional quality of whole-plant corn for silage. This study was performed in a commercial 1,900-cow dairy farm located in Piedritas (Buenos Aires, Argentina). Two commercial hybrids (A and B) were planted in experimental plots within a cornfield destined for corn silage. Hybrids were sown at a theoretical seeding rate of 60,000, 70,000, 80,000, and 90,000 seeds/ha in 4 replicates per hybrid. Plots were eight 50-m-long rows separated by 52cm. Corn was planted with a no-till seeder equipped with a pneumatic dosing machine. Ten plants within each plot were cut by hand at 15cm above ground. Whole plants were chopped, weighed, mixed thoroughly, and frozen until analysis. Nutritional composition was determined by near-infrared reflectance spectroscopy. Harvesting occurred at one-quarter milk-line [31.4% dry matter (DM)] and one-half milk-line (34.5% DM) stages of maturity for hybrids B and A, respectively. No interactions between hybrid and planting density were observed for any of the variables of interest. Planting density did not affect either plant DM weight or DM, crude protein, neutral detergent fiber, acid detergent fiber, or starch concentrations of whole-plant corn. Dry matter yield was significantly increased at higher planting densities. The similar per-plant biomass and nutritional quality among different densities can be explained by the abundant precipitation observed during this growing season (719mm since the beginning of fallow until harvest). In conclusion, greater yields of silage can be obtained by increasing corn planting density without affecting its nutritional composition, although the effect of planting density with limiting resources (e.g., precipitation) still needs to be elucidated.

Short communication: Effect of corn planting population on phosphorus concentration and uptake in corn silage

“…In another recent on-farm study, Ferreira and Teets (2017) also reported higher forage yields when corn planting population was increased from 55,000 to 100,000 plants/ha. In addition to the increased yields, the latter studies (Ferreira et al, 2014;Ferreira and Teets, 2017) reported similar nutrient composition of the forages obtained when corn was planted at different planting densities.…”

“…Cusicanqui and Lauer (1999) reported that the greatest DM yield was obtained when corn plant density was increased to approximately 98,000 plants/ha. Ferreira et al (2014) reported that forage yields increased linearly and by 41% when plant density was increased from 60,000 to 90,000 plants/ha. In another recent on-farm study, Ferreira and Teets (2017) also reported higher forage yields when corn planting population was increased from 55,000 to 100,000 plants/ha.…”

“…Control of water runoff and erosion refers to practices that reduce the potential for P delivery to bodies of water (Bosch et al, 2006). Whether increasing the corn planting population increases P uptake from the soil, and therefore can reduce P runoff to bodies of water, has not been reported (Ferreira et al, 2014;Ferreira and Teets, 2017). We hypothesized that increasing the corn planting population increases P uptake from the soil through corn silage.…”

The optimal plant density of maize for dairy cow forage production

“…This limiting effect on the biomass yield should be attributed to the intense inter‐plant competition (Jia et al., 2018; Zhang et al., 2018). When the plant density exceeds optimal value, intraspecific competition passively affects the transformation and assimilation of nutrients, thereby limiting any gains in crop productivity, and resulting in reduced yield (Boomsma, Santini, Tollenaar, & Vyn, 2009; Ferreira et al., 2014; Qiang et al., 2019). Furthermore, with increasing plant density, the plant water content increases and the proportion of dry matter decreases (Table 3), in agreement with Dragičević et al.…”

“…The consumption of maize used as livestock forage increased from 85 million tons in 2000 to 157 million tons in 2018 (Jiang, 2018). In the dairy industry, whole maize plant (WMP) silage is a primary source of energy and fiber for dairy cows (Ferreira, Alfonso, Depino, & Alessandri, 2014).…”