Jasper County Soil and Water Conservation District
These samples are the same soil type and have been in a corn-bean rotation for the past 20+ years, however their treatment has been substantially different. The soil on the left has not been tilled or had anhydrous ammonia applied for over 20 years and has had a cereal rye cover crop grown after harvest for the last 5 years. The soil on the right has been tilled each year, as well has had anhydrous ammonia applied in the fall. This picture was taken about 2 minutes after the samples were submerged in water.
The tilled soil essentially “exploded” as soon as it entered the water. Repeated tillage has destroyed the structure of the soil, eliminating pore space and destroying the biological “glue” that helps hold soil together, and as a result the soil has collapsed. In contrast, due to minimal soil disturbance the tillage-free soil has excellent pore space and extensive biological activity, and as a result has provided the soil with a healthy structure that can withstand the impacts of water.
Within 5 minutes the tilled soil was completely gone, whereas the tillage-free soil remained almost entirely intact. We decided to see how long it could last and kept adding water to it (to keep up with evaporation) over the course of several weeks. We gave up after 6 weeks, in which the tillage-free soil sample was still about 95% intact.
For those of you asking about yield differences, we were able to gather some information from these two farmers. Keep in mind that this isn’t an official scientific research article, but merely a comparison of two farming operations based on a conversation with each farmer and a simple demonstration of their soil. As mentioned in the original post, these are the exact same soil type and the samples were collected on the same day.
The tillage farmer has a 10 year average of 210 bu/acre whereas the no-till farmer has a 10 year average of 187 bu/acre, so if you’re looking purely at yield then the tillage farmer has a 12% higher yield compared to the no-till farmer. However, when it comes to long term no-till the bulk of the benefits come from reduced inputs and more resilient soil. The tillage farmer applies 170 lbs/acre of nitrogen for his corn crop, whereas the no-till farmer is only applying 120 lbs/acre (and even less in some years). So the tillage farmer is applying 41% more nitrogen but only getting a 12% higher corn yield. When it comes to phosphorus and potassium, the tillage farmer is applying both nutrients ahead of corn. The no-till farmer has not applied phosphorus or potassium for the past 7 crop years.
When it comes to field work, the no-till farmer has substantially less to do, resulting in significantly lower fuel and labors costs, as well as reduced wear and tear on his equipment. After he harvests his crops in the fall he drills a bushel/acre of cereal rye as a cover crop and he’s done with field work for the year. That’s it. When it comes to the tillage farmer’s post-harvest field work, he has the co-op spread his P and K fertilizer (before corn) and then he works it in with tillage. Later in the fall he has anhydrous ammonia applied (before corn). The following spring he does 2 more passes of tillage before a pre-emergent herbicide application and planting his cash crop. The no-till farmer’s spring field work consists of terminating the cover crop and then planting his cash crop. He applies his nitrogen to his corn after emergence in the form of 32% liquid nitrogen. After crops are up and growing they both have relatively similar herbicide programs most years.
So as we mentioned above, if you’re looking purely at yield as your indicator for success, then the tillage farmer has the edge. However, the no-till farmer’s inputs are significantly less than the tillage farmer’s. He’s spending less on fertilizer, fuel, and labor, and his equipment is experiencing a fraction of the wear and tear of the tillage farmer’s equipment. As a result of these lower input costs his profit margin is higher, even though his yields are slightly less. And all of this is only considering the financial numbers behind tillage vs. no-till and not the impact that these two different farming operations have on the soil. The no-till farmer is experiencing little to no erosion each year, and his soil is more resilient to both drought and heavy rains due to its impeccable structure and vast biological activity. On the other hand, the tilled soil is eroding at significant rates and doesn’t hold up to drought and water as well as the no-till soil, as you’ve seen in the picture above.
These numbers and figures we’ve provided are for 2 specific farming operations in central Iowa, and as we all know, each and every farm is a little bit different. We can’t expect to apply these numbers to every single tillage farmer or every single no-till farmer, however the basic concepts behind what tillage and mechanical disturbance does to the soil is universal. Tillage destroys the structure of the soil, eliminating pore space and causing the soil to collapse in on itself, making it more susceptible to erosion. We posted this picture with the hopes that we could reach a few people and get them thinking about the soil. We had no idea it would reach this far and start such an expansive dialogue throughout people across the entire country, and we are beyond ecstatic about it.
These samples are the same soil type and have been in a corn-bean rotation for the past 20+ years, however their treatment has been substantially different. The soil on the left has not been tilled or had anhydrous ammonia applied for over 20 years and has had a cereal rye cover crop grown after harvest for the last 5 years. The soil on the right has been tilled each year, as well has had anhydrous ammonia applied in the fall. This picture was taken about 2 minutes after the samples were submerged in water.
The tilled soil essentially “exploded” as soon as it entered the water. Repeated tillage has destroyed the structure of the soil, eliminating pore space and destroying the biological “glue” that helps hold soil together, and as a result the soil has collapsed. In contrast, due to minimal soil disturbance the tillage-free soil has excellent pore space and extensive biological activity, and as a result has provided the soil with a healthy structure that can withstand the impacts of water.
Within 5 minutes the tilled soil was completely gone, whereas the tillage-free soil remained almost entirely intact. We decided to see how long it could last and kept adding water to it (to keep up with evaporation) over the course of several weeks. We gave up after 6 weeks, in which the tillage-free soil sample was still about 95% intact.
For those of you asking about yield differences, we were able to gather some information from these two farmers. Keep in mind that this isn’t an official scientific research article, but merely a comparison of two farming operations based on a conversation with each farmer and a simple demonstration of their soil. As mentioned in the original post, these are the exact same soil type and the samples were collected on the same day.
The tillage farmer has a 10 year average of 210 bu/acre whereas the no-till farmer has a 10 year average of 187 bu/acre, so if you’re looking purely at yield then the tillage farmer has a 12% higher yield compared to the no-till farmer. However, when it comes to long term no-till the bulk of the benefits come from reduced inputs and more resilient soil. The tillage farmer applies 170 lbs/acre of nitrogen for his corn crop, whereas the no-till farmer is only applying 120 lbs/acre (and even less in some years). So the tillage farmer is applying 41% more nitrogen but only getting a 12% higher corn yield. When it comes to phosphorus and potassium, the tillage farmer is applying both nutrients ahead of corn. The no-till farmer has not applied phosphorus or potassium for the past 7 crop years.
When it comes to field work, the no-till farmer has substantially less to do, resulting in significantly lower fuel and labors costs, as well as reduced wear and tear on his equipment. After he harvests his crops in the fall he drills a bushel/acre of cereal rye as a cover crop and he’s done with field work for the year. That’s it. When it comes to the tillage farmer’s post-harvest field work, he has the co-op spread his P and K fertilizer (before corn) and then he works it in with tillage. Later in the fall he has anhydrous ammonia applied (before corn). The following spring he does 2 more passes of tillage before a pre-emergent herbicide application and planting his cash crop. The no-till farmer’s spring field work consists of terminating the cover crop and then planting his cash crop. He applies his nitrogen to his corn after emergence in the form of 32% liquid nitrogen. After crops are up and growing they both have relatively similar herbicide programs most years.
So as we mentioned above, if you’re looking purely at yield as your indicator for success, then the tillage farmer has the edge. However, the no-till farmer’s inputs are significantly less than the tillage farmer’s. He’s spending less on fertilizer, fuel, and labor, and his equipment is experiencing a fraction of the wear and tear of the tillage farmer’s equipment. As a result of these lower input costs his profit margin is higher, even though his yields are slightly less. And all of this is only considering the financial numbers behind tillage vs. no-till and not the impact that these two different farming operations have on the soil. The no-till farmer is experiencing little to no erosion each year, and his soil is more resilient to both drought and heavy rains due to its impeccable structure and vast biological activity. On the other hand, the tilled soil is eroding at significant rates and doesn’t hold up to drought and water as well as the no-till soil, as you’ve seen in the picture above.
These numbers and figures we’ve provided are for 2 specific farming operations in central Iowa, and as we all know, each and every farm is a little bit different. We can’t expect to apply these numbers to every single tillage farmer or every single no-till farmer, however the basic concepts behind what tillage and mechanical disturbance does to the soil is universal. Tillage destroys the structure of the soil, eliminating pore space and causing the soil to collapse in on itself, making it more susceptible to erosion. We posted this picture with the hopes that we could reach a few people and get them thinking about the soil. We had no idea it would reach this far and start such an expansive dialogue throughout people across the entire country, and we are beyond ecstatic about it.
