Field Crop Production - Introduction

Table of Contents

1. Conventional tillage leaves less than 30% residue
2. Mulch tillage leaves more than 30% residue
3. Available in Published Version of Field Crop Production

Producing high yields has always been an important part of farming. When input costs were low compared to crop returns, the best way to farm was to fertilize for maximum yields and then, add a little extra. The feeling was that you could lose more with too little input than with too much.

Figure 1. Conventional Tillage.

With the costs of fertilizer, fuel and other inputs increasing and crop prices not keeping pace, the emphasis has changed. Inputs are carefully measured so that the yield for each unit is worth more than the cost of the input. The greatest yields do not necessarily give the greatest profit.

Conventional tillage leaves less than 30% residue

In recent years, the focus has widened to include environmental factors in the crop production equation. It is no longer acceptable to ignore what happens beyond the fence because of the way we farm.

Figure 2. Mulch Tillage.

Best management practices are tools for meeting today's agricultural goals. To be a best management practice, an action must maintain or increase crop returns while minimizing the impact on the environment. There is no one system for all farms. The combination of practices appropriate for your farm will depend on individual problems and opportunities.

Mulch tillage leaves more than 30% residue

The first part of this book will help you understand the basics such as soil management, residue management, crop rotation, pest management, nutrient management as well as the importance of using a systematic approach to change. The next three sections focus on different types of tillage, conventional tillage, mulch tillage, and no-till/ridge tillage. And finally, the book provides some non-tillage options that improve the environment.

The book cannot provide you with all the possible information. Rather, it gives you the basics and provides references for further reading. Some terms used may be unfamiliar. To avoid confusion, we are using the following definitions for the different types of tillage:

Conventional tillage is any system which attempts to cover most of the residue, leaving less than 30% of the soil surface covered with residue (or crop remains) after planting. Usually, the moldboard plow is used along with a variety of other tillage tools.

Mulch tillage is any system where soil is disturbed between harvesting one crop and planting the next. However, in this case, more than 30% of the soil surface is left covered with residue after planting. Chisel plows, offset discs or modified moldboard plows are the common implements. Other terms that you may hear to describe this system are reduced tillage, minimum till or conservation tillage.

Figure 3. No-till.

No-till is any system where the soil is not disturbed between harvesting one crop and planting the next. Some tillage may be done by attachments to planting equipment to assist seed and fertilizer placement.

Figure 4. Ridge tillage.

Ridge tillage is a specific form of no-till where crops are planted on pre-formed ridges. Inter-row cultivation is done after the crop has emerged in order to control weeds and re-form the ridges.

You may wish to change your cropping system for many different reasons such as: to save money, to increase yields, to save labour, to solve erosion problems, or to reduce pesticide use. Whatever the reason, the first stage of change is to assess where you are now and what your goals are. Once you have done that, this book should help outline some of the options available. Good luck!

Table 1. Advantages and Disadvantages of Tillage Systems

Conventional Tillage

Advantages

• Familiar to most farmers and machinery widely available.
• Incorporates manure without specialized equipment.
• Soil warms faster in the spring than with less tillage.
• Allows maximum frost action on soil. This breaks the soil into smaller clumps.
• Low levels of surface residue permit high levels of water evaporation. This allows earlier planting and is a plus for poorly-drained soils.

Disadvantages

• More equipment is needed than in reduced tillage systems.
• Low residue levels make soil vulnerable to crusting and erosion by wind and water.
• Tillage stimulates weed growth and reduces levels of organic matter.
• Working wet soil may cause compaction and the development of plow pans.
• During the growing season, high evaporation resulting from lack of residue can reduce crop yields.

Mulch Tillage

Advantages

• Most of the same advantages as conventional tillage.
• Residue left on soil surface reduces erosion and water run-off.
• Labour inputs are lower than in conventional tillage.
• Fewer trips over the field reduce costs.
• Management skill levels required similar to conventional tillage.

Disadvantages

• Tillage stimulates weed growth.
• High residue levels can slow soil warm-up in the spring.
• Primary tillage will not be effective under wet conditions.
• High residue levels require attachments on the planter.

No-Till/Ridge Tillage

Advantages

• Lower input and capital expenses.
• Labour inputs per acre are greatly reduced.
• More organic matter is located near the surface, which improves soil structure.
• High levels of residue drastically reduce soil erosion.
• Increased biological activity in soil, which improves structure and increases the speed of pesticide breakdown.

Disadvantages

• High residue levels can slow soil warm-up.
• Success depends on the characteristics of the soil.
• Fewer options are available to work in manure.
• Above-average management skills are required.

Available in Published Version of Field Crop Production

• Reasons to Consider Changing Your System - Chart
• Corn Yield Index - Chart
• Energy Requirements for Different Tillage Systems - Chart
• Off-farm Concerns
• Learning Costs

Best Management Practices: Field Crop Production