Corn Fertility Irrigation | Delaware Agronomy Blog

Category: Fertility (page 2 of 4)

2023 Interactions Between Nitrogen, Planting Population, and Irrigation for Corn

October 28, 2023 / Jarrod Miller / Comments Off

Jarrod Miller, James Adkins

Quick summary: Irrigation boosted yields in southern Delaware by 30 bushels. Under irrigation, N-rates of 200 lbs averaged 247 bushels of corn, while maximum yield occurred at populations of 36,000 seeds acre^-1. Rainfed conditions suppressed K uptake in the plant, while the opposite effect was observed with Mg.

**Figure1:** Research plots at the UD Warrington Irrigation Research Farm. Interactions include planting rates, nitrogen rates, and rainfed versus irrigated plots.

As part of research supported by the Maryland Grain Producers (https://marylandgrain.org/), we planted corn under irrigated and rainfed conditions under a range of populations (20-40,000 seeds acre^-1) and nitrogen (N) rates (75-300 lbs acre^-1). This research was performed at the University of Delaware Warrington Irrigation research farm (Harbeson, DE) in the summer of 2023 (Figure 1), where variable rate irrigation was used to create rainfed conditions across the field.

Effects of Cover Crops and Nitrogen Rates on Corn Yields

September 28, 2023 / Jarrod Miller / Comments Off

Quick summary: When available soil N is lower, rye cover crops may occasionally reduce yields while clover cover crops may occasionally improve yields. At adequate fertilizer levels, yields are not affected by cover crops on sandy, Delaware soils.

**Figure 1:** Corn nitrogen rate trials following cover crops in Georgetown, DE in the summer of 2023.

As part of the Precision Sustainable Agriculture network (https://www.precisionsustainableag.org/), a study was deployed across multiple states to examine the nitrogen (N) cycling that occurs with cover crops. Plots of rye, clover, and a rye-clover mix were seeded each fall over three years (2020-2023). In the spring, plots were terminated two weeks prior to corn planting and then sidedressed to reach total N rates between zero to 320 lbs N/acre. The visual response of the variable N-rates can be observed in Figure 1.

Fall Establishment of Small Grains for Tillers

September 21, 2023 / Jarrod Miller / Comments Off

Proper establishment of small grains will ensure success when springtime temperatures begin to warm. Some practices that help with planting include germination tests, tillage (after corn), and planting during the optimal window (https://sites.udel.edu/weeklycropupdate/?p=12483). When considering planting rates, research at UD has not seen increased yields above 1.5 million seeds per acre (https://sites.udel.edu/agronomy/2020/10/01/2018-2020-wheat-seeding-rate-yields/). This follows many regional recommendations, but without good seed to soil contact, moisture, or N, you may still have a slow start.

Grid Sampling Soils to Improve Understanding of Soil Variability

March 22, 2023 / Jarrod Miller / Comments Off

Jarrod Miller and James Adkins, University of Delaware

Variability in soil land landscape characteristics reduces yield response to management techniques, particularly regarding seeding rates and fertilizer additions. Yield maps provide a spatial map of yield, which can be associated with drainage issues, soil nutrient holding, or nutrient concentrations. One method to uncover soil variability and crop response is to use precision soil sampling, including either grid or zone methods. Both increase the cost of taking soil samples, and each have their value depending on the desired outcomes.

Exchangeable Cation Uptake by Irrigated and Rainfed Soybeans (2021-2022)

October 5, 2022 / Jarrod Miller / Comments Off

Although Ca, Mg, and K are all exchangeable nutrients that are considered plant available, soil chemistry and plant root interactions result in different uptake and bioavailability. Within the soil, Ca and Mg can move with soil water or by diffusion, while the lower K concentrations do not readily move with soil water. This results in differences in uptake for soils with adequate moisture versus those under drought stress. Understanding how concentrations of each nutrient, the soil CEC, and soil moisture content interact is important for giving future nutrient recommendations.

Irrigated and rainfed dry corners in a Delaware field.

Delaware Agronomy Blog

University of Delaware Cooperative Extension

Category: Fertility (page 2 of 4)

2023 Interactions Between Nitrogen, Planting Population, and Irrigation for Corn

Effects of Cover Crops and Nitrogen Rates on Corn Yields

Fall Establishment of Small Grains for Tillers

Grid Sampling Soils to Improve Understanding of Soil Variability

Exchangeable Cation Uptake by Irrigated and Rainfed Soybeans (2021-2022)

Archives

Categories

Monthly Archives

Article Categories

Subscribe By Email