Best Management Practices for Growing Maize on Dairy Farms

5. Soil preparation• The soil provides water andnutrients to the crop, but poorlymanaged cultivation can damagesoil and affect crop yields• Factors to consider are:- Soil type and suitability <strong>for</strong>cultivation- Adjacent sensitive areas (e.g.waterways)- Quality of the final seed bed(uni<strong>for</strong>mity of surface andaggregate size)- Intensity of cultivation, includingthe pros and cons of ploughingThe soil provides water and nutrients <strong>for</strong>plant growth; there<strong>for</strong>e, a healthy (structurallysound and biologically active) soil isimportant <strong>for</strong> crop production.Cultivation serves many purposes in cropestablishment.• Creating a uni<strong>for</strong>m seed bed• Relieving compaction (e.g. from stocktreading) and improving aeration• Incorporating residues and weeds• Warming and drying the soil• Incorporating lime and fertilisersPoorly timed or managed cultivation candamage soil, cause compaction anderosion problems, and ultimately affectcrop production. This is most likely to occurwhen the soil is too wet or too dry.Some of the key steps <strong>for</strong> successful cultivationare outlined here:1. Understand your soil resourceHow your soil responds to cultivationwill depend on the soil type and texture,plus any limitations it may have such asrisk of erosion and water logging. Yourregional council can help you to identifyyour soil type and any limitations it has <strong>for</strong>cropping.2. Identify sensitive areasSoil can run off into water ways during highrainfall events, creating erosion and waterquality issues. Most regional councils haveguidelines <strong>for</strong> how close you can cultivateto a waterway. If you need to leave a bufferzone around the edge of your cultivatedzone, don’t spray it out as weeds will establishinstead. Rank grass vegetation will actas a filter and help trap potential run off.3. Soil surface<strong>Maize</strong> seed is normally sown around 5 cmdeep. An uneven soil surface (undulations,ruts etc) makes it difficult <strong>for</strong> the planter toplace the seed at a uni<strong>for</strong>m depth, resultingin variable emergence. Very cloddysoil or large ruts can cause the planter tobounce, causing variability in seed depthand spacing.4. Aggregate size<strong>Maize</strong> does not need a very fine seedbed.It is a large seed and seed to soil contact isgenerally sufficient <strong>for</strong> germination, exceptin very cloddy soils. Light rolling aftersowing may help improve the seed-soilcontact, seal in moisture and reduce therisk of wind erosion.5. Minimal cultivationExcessive cultivation weakens the soil andaccelerates loss of soil organic matter.Keep cultivation to a minimum and avoidcultivation when the soil is too wet or too dry.10