Residue and Compaction Management

No-till is becoming more popular because it reduces soil erosion, improves water conservation, and decreases labor requirements. Unfortunately, the crop residues that protect the soil surface from erosion in no-till systems may reduce com yields by slowing soil warming in the spring. One way to solve this problem may be to clear residues from the seed row, while leaving the rest of the soil surface residue covered

Cover Crop Selection and Management for Agronomic Farming Systems

Cover crops can extend the season of active nutrient uptake and living soil cover and thereby reduce nutrient losses in water and sediment. The conversion of the prairies or other native vegetation ecosystems to summer annual grain crops resulted in a shortening of the season of living plant cover and nutrient uptake. Summer annual grain crops, like corn and soybean, accumulate water and nutrients and provide living cover for only about four months (mid-May to mid-September), whereas in natural systems, some living plants are actively accumulating nutrients and water whenever the ground is not frozen (at least 7 months; April-October). As a result, soil nutrients in summer annual cropping systems are susceptible to losses in part because there are periods during each year when active plant uptake and soil cover are absent

Small Grain Cover Crops for Iowa

Cover crops are literally crops that cover the soil and are primarily used for erosion control. For most of the Midwest where com and soybean are grown, cover crops would have to be grown between harvest and planting. Unfortunately, in the upper Midwest (especially north of I- 80) the potential growing season for cover crops is usually short and cold, thus limiting their growth and effectiveness. This problem can be partly solved by overseeding cover crops into either com or soybean in mid-August to early September. Additionally for crops that are harvested relatively early, such as silage com, seed com, or early-maturing soybean, a winter-hardy small grain cover crop can be planted with a grain drill or incorporated with shallow tillage before late October

Disease risks associated with cover crops and soybean production

Cover crops have numerous environmental benefits, for example reducing erosion, improving infiltration, mitigating nutrient loading in surface waters, and improving soil health (Kaspar et al 2001, Kaspar and Singer 2011, Schnepf and Cox 2006). Still, some farmers are reluctant to introduce cover crops into their production systems. In a 2016 Cover Crop Survey, approximately 30 percent of the respondents stated that “increased disease potential” was a minor or major challenge to using cover crops on their farm (SARE, 2016). Of the respondents, 20 percent had been growing cover crops for 2-3 years, 30% for 4-5 years, and 19% for more than 10 years. The goal of our research is to understand how cover crop may affect disease potential in the following cash crop and thereby recommend actions that may be taken to mitigate disease risk

Corn Planter Attachment Effects on Soil and Residue

In recent years, an increasing amount of Iowa row crops have been planted into soil left undisturbed from the prior year\u27s harvest. In 1994, one of five Iowa row crop acres was planted in a no-till system (NRCS, 1994). \u27Various planter modifications and attachments are marketed to assist planting into undisturbed soil. The attachments are sometimes used also after full-width tillage such as a field cultivation or disking. Planter operators use the attachments to improve planting by moving residue or uneven soil clods from the row area or to assist seed placement in wetter than ideal soil conditions. Row cleaners and strip tillage devices impact the amount of residue cover left over the row after planting. Coulters that till soil in the seed zone affect soil around the seed. Decisions on the use and management of com planter attachments can be made by considering their effect on residue cover over the row area and soil conditions in the seed placement zone within the row

Maize system impacts of cover crop management decisions: A simulation analysis of rye biomass response to planting populations in Iowa, U.S.A.

Cover crops provide environmental services that can effectively reduce the negative impacts from otherwise highly productive row-crop systems in the US Midwest. In this context, winter rye [(Secale cereale sp.)] is the most commonly used cover crop among producers because it overwinters and produces considerable biomass in the spring. While the soil and water benefits of a maize-rye system are well documented, the extent to which these benefits change under different rye planting densities has not been fully explored. In particular, shoot-biomass of a fall-seeded rye cover crop is expected to respond to increasing plant populations (PP), influence maize system productivity overall, and provide additional income for growers to justify the higher establishment costs of the cover crop. Field data for a long-term biomass assessment is costly and hard to generalize, so we used 25-year weather records to run the field-scale model APSIM at three Iowa locations to: 1) Quantify the relationship between rye biomass and rye PP, 2) Test if this relationship is further controlled by maize Nitrogen (N) rates or vary across locations and soil types, 3) Investigate if changes in maize system outcomes, i.e. grain yield, nitrate leaching, soil erosion, and runoff are significantly related to rye biomass, and 4) Estimate changes in farm returns for maize operations that utilize rye biomass under alternative management scenarios (i.e. grazing). Overall, we found a positive relationship between rye biomass and PP, with spring biomass increasing by 30% when populations double. No evidence for a biomass plateau was found, although spring biomass differed by soil type and location. Relative changes in soil erosion and N-leaching were negatively correlated with rye biomass (−30 and − 25% change relative to no cover crop, p \u3c 0.01). Further, for a 200-acre (≈80 ha.) maize-cattle operation, the rye cover crop was shown to impact maize yields minimally albeit reducing annual farm income across Iowa when its biomass is not grazed (−4149 to −5198 $. year−1); or even when grazed early (−1800 to −3321$. year−1). Late grazed rye could help farmers to turn positive returns in central and southern locations (+2688 to +6902 $. year−1) but not in northerly areas. Results from this study indicates that cover crops could effectively benefit maize system performance overall although the economic incentives for increasing rye populations are not applicable to every location in Iowa