All farmers are keenly aware of the importance that water plays in growing good crops. This is especially pertinent on the High Plains where total rainfall is not high, humidity is low, and open-pan evaporation rates are often 2-3 times higher than total rainfall. A big part of crop production in our area has been focused on “keeping” water in the system. Leaving more residue on the surface was an obvious step in the right direction to achieve this goal and new technologies came forward throughout this areas’ history that aided this process. Full notill (zero-tillage)management is the most recent technology for residue management for the purpose of minimizing water losses to evaporation.
In the early days (pre-1930) the moldboard plow was the tool of choice.
In the 1930′s a new technology came about that allowed for leaving a higher percentage of residue on the surface during weed control operations. This was called the “one-way” and was extensively used until the 1960′s.
In the 1960′s another new implement came out that left yet more residue on the surface while doing an excellent job in killing weeds and controlling field “smoothness”. The large blade undercutter was widely used in the 1970′s-1990′s and even today it is not uncommon to see one in operation.
Although all producers understood the advantages that more residue had on the surface (primarily shading the soil and breaking up rain drops), it wasn’t until the past 20 years where we began to understand the other major impacts notill management has on production agriculture in this area.
On the water side
Leaving 100% of the residue on the surface can ultimately lead to zero exposure of the soil to sun and wind forces that steal water from us.
This picture shows stripped wheat stubble that has recently been planted to corn. The cap is lying right on a row. Notice that no soil is exposed and there is a thick thatch layer on the soil that aids in keeping soils moist and cool.
Rain droplets come at such force that if they hit the soil then they break soil peds down eventually sealing the soil surface so that water begins to pond on the surface. It was often estimated that once a rainfall event got started that a tilled field could absorb about 0.25-0.50″ of moisture before becoming sealed. Crop residue on the surface takes the shock from the rain drops and breaks them apart so that by the time they are impacting the soil surface little damage can be done. Another aspect of getting rainfall into a soil is macro-pore space. This space is created by old crop roots, insects, earth worms and other activities that create vertical and horizontal cavities primarily in the top foot of soil. These macro-pores allow water to find easier pathways to get down to deeper soil horizons and consequently notill soils with good macro-pores can swallow a lot of moisture very quickly. We have seen 4-5″ rain events completely absorbed in our notill fields while on conventional tilled fields the majority of this water is either sitting on the surface or running off into pastures and creeks. Tillage DESTROYS these macro-pores.
This picture shows where soil (nutrients, organic matter, etc.,) go after a heavy rain event on conventionally tilled ground. Ephemeral gullies can be see on the ground and the water came off this field so hard and fast that it even took out a lot of the native grasses shown in this picture. Much of this field ended up in a pasture pond after this event.
Extreme erosion events are possible when sloping ground is conventionally tilled.
As shown in this picture, almost 6′ of soil has been removed by a single rain event on this conventionally tilled ground (note shovel in foreground).
Macro-pores are also critical components for exchanging gases, nutrients and provide least resistant pathways for plant roots.
Notill management is here to stay on the High Plains and within a generation tillage will be gone. From the 1930s-1980s this area was primarily in a wheat-fallow rotation where one crop was harvested every two years. In the 1990′s notill allowed us to put a corn or milo crop behind the wheat stubble (traditional eco-fallow rotation) meaning that we were now growing two crops in three years. Today, a common rotation is wheat-corn-milo-fallow, which leads to three crops in four years. Experimentally, other crops are coming into the mix like soybeans, sunflowers, yellow peas, millet, etc., and it won’t be long before summer fallow is completely eliminated and we are simply growing a crop every year. The amazing part of all of this is that even though we are increasing cropping intensity (crops per years), our yields are actually going up substantially. Yields that were unheard of in this area 20 years ago are becoming commonplace today. It is not unusual to see 70+ bu/ac wheat, 120+ bu/ac corn or milo and 30+ bu/ac soybeans. Not to say that we are completely immune from droughts, freezes and other extreme weather but rather notill is allowing us to improve our water use efficiency to the point where we can reliably grow more crops, with higher yields, a larger percentage of the time.
Here is us in the “old days”. The soil is blowing and notice how “dead” the ground looks. Almost like a Martian surface.
In this picture a notill corn crop is shown planted into wheat residue. Notice that no soil is exposed and the good health of the plants even on the lower leaves.
Even our summer fallow ground looks vastly different today. This is a picture right at wheat drilling time. The wheat stubble in the picture was a crop grown 3 years previous while the corn stalks were from the previous year. With conventional till summer fallow we are able to “save” only 25% of all incoming moisture during the fallow period, with notill summer fallow we are saving 40% of all incoming moisture which means that we are still leaving a lot of moisture on the table in a rotation that uses summer fallow.
Crop rotation is a critical aspect of proper notill management and can be used to reduce weed and insect pressures as well as take advantage of naturally symbiotic crop mixes (like pulse crops and wheat). Rotation provides other advantages as well such as spreading labor and equipment over a larger time window. For example, yellow peas are planted in March, corn in April & May, soybeans in May, grain sorghum in May and June and wheat in September and October. Our grain drill is hooked up four months of the year while our planter is running across three months of each year. This allows us to cover more acres per piece of equipment. Environmental risks are also mitigated with more crop rotation/diversity. In Western Kansas, it is not uncommon to have both drought conditions and high rainfall periods within the same year; we just don’t know when they will occur. Having different crops growing that require moisture at different times of the year allows us to “ensure” that some of our crops will be successful, while minimizing the impacts (economically) of short-term drought within a given year.
Fertilizer management is a critical aspect of notill to ensure ever increasing yield plateau’s for each crop type. A significant upside to notill management comes in the form of reducing fertilizer pollution (where fertilizer runs off the fields after rainfall events or leaches into water tables). Notill soils also have increased soil organic matter and more active soil biology which allow much more nutrient buffering to take place. On our farm we use crop removal based variably rate applied fertility and this is discussed more on the technology page.
Soils are living breathing organisms and should be treated as such. They have their own microbiology that adds up to about 2000 pounds per acre of bacteria, fungi, nematodes, earthworms, etc.,). This biology cycles nutrients, pulls nutrients from the atmosphere, helps plants more efficiently use nutrients and water and keeps things in balance. Tillage DESTROYS this biology. When using tillage a person is dealing with an almost dead, sterile seed bed. This doesn’t mean crops can’t be grown, but rather it takes a lot more nutrients and water to get the same yields as one can in notill management.
Growing winter wheat planted into soybean residue. Notice also the corn residue that was grown before the soybeans.
Rolling ground with wheat planted into soybean residue. Again corn stalks from the crop before the soybeans are still present and one can see that even on such rolling ground there are no signs of water erosion.
A major plus to notill management has been to minimize soil erosion (through either wind or water forces). We are keeping our soil in place and building it back to more “natural” levels of microbiology and fertility. The dustbowl days are over for much of the High Plains but as evidenced this past year in Colorado (where 6 people lost their lives in a massive accident on I-70 due to blackout conditions) there are still some areas that have not widely adopted notill practices.
Wildlife has become more abundant as our area has moved to notill production. I can’t think of animal that has not benefited from notill management. From increased protection and nesting habitats for peasants, quail and other birds, to increased food sources for deer, turkey and coyote the wildlife populations have exploded in the past 15 years. Naturally, this creates other opportunities for our local area economy in terms of increased tourism due to hunting.
A zero-tillage approach is a win-win for everyone. The producer can better utilize water and grow better crops more frequently. The landowner sees increasing rent as well as their property increases in value as the soils are built up and prevented from eroding away. Environmentalists value the carbon we are storing in the ground (in the form of stable organic matter) as well as the reduced pollution notill management incurs (less fertilizer run-off, minimized soil erosion, reduced air pollution, less chemical usage as proper crop rotation can minimize the need for herbicides, pesticides and even fertilizer). The local economy wins as farms are more productive and more money is coming into the local equation as notillers continue to grow more crops, more frequently. Hunters and wildlife lovers can take advantage of the abundance of animals thriving in habitats more conducive to their survival.
We are really just in the infancy stages of notill adoption in that we don’t have a lot of long-term research studies to draw from or practical hands-on experience with many facets here on the High Plains. Notill management is bringing in some new problems that will have to be better understood and remedied. For example, leaving a 100% residue on the surface the year around creates a much different micro-climate at the soil level. This micro-climate tends to stay moist, have higher levels of humidity, has more temperature stability and provides a good habitat for fungi, bacteria, insects and other yield reducing organisms. Consequently, we are spending more time looking at fungicide and insecticide applications on our dryland acres.
Notill management has really made farming a lot more exciting, intellectually challenging and more profitable, but one must always be striving to push the envelope and stay in front of the curve regarding this technology as things are happening fast and one can’t get behind one’s neighbors in adoption of new methods. Land values and cash rents are driven by the expected productivity of farm ground and consequently it’s not surprising that there are wide ranges of cash rent values being used in the area as we still have farmers growing one crop in two years while others are growing a crop every year.