|Anderson, Randal - Randy|
Submitted to: Agricultural Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2011
Publication Date: 1/13/2012
Citation: Merrill, S.D., Tanaka, D.L., Liebig, M.A., Krupinsky, J.M., Hanson, J.D., Anderson, R.L. 2012. Sequence effects among crops on alluvial-derived soil compared with those on glacial till-derived soil in the northern Great Plains, USA. Agricultural Systems. 107:1-12. Interpretive Summary: The Northern Great Plains Research Laboratory (NGPRL) of the USDA-Agricultural Research Service has defined the concept of a dynamic cropping system, which is an annual strategy of crop species choices to achieve longer-term agronomic, economic, and environmental goals. In order to implement the dynamic cropping systems concept, it is essential for agriculturalists to have information about how one year’s crop species affects the growth of the following year’s crops. The NGPRL has completed two large-scale crop sequence experiments where all the interactions among two groups of ten crops each (16 different species altogether) were observed using no-till management. These experiments were done on silt loam, glacial till-derived soils. In order to assess the effect of soil type on crop sequence effects, we have conducted a sequence experiment among four crop species – spring wheat, dry pea, soybean, and corn on sandy loam, alluvial-derived soil. Crops were able to grow roots and extract water more deeply in the sandy loam soil than in the silt loam. Yields of spring wheat and dry pea did not generally vary significantly between the two soil types. However, when a direct comparison was made, corn yields were found to be lower on the silt loam soil, and yield of corn-following-corn was about half of that on sandy loam soil. Corn uses more soil water than the other crops, and subsoil in the silt loam soil wasn’t as good at allowing soil water to infiltrate through or at passing it on to plants. Comparisons of the sequence effects of the crops on spring wheat showed a generally common pattern of relative yield values across all three experiments for years with adequate precipitation – prior dry pea had neutral to positive effect (nitrogen production and soil water conservation); prior spring wheat, negative (disease); soybean, positive (nitrogen production); prior corn, neutral to negative (heavier soil water use).
Technical Abstract: To implement the dynamic cropping systems concept, agriculturalists need information about how crop species affect following years’ crops. Little research exists about how soil type affects crop sequence dynamics. Sandy loam, alluvial soil in North Dakota was the site of a crop sequence experiment under no-till management in which four crops – maize (Zea mays L.), dry pea (Pisum sativum L.), spring wheat (Triticum aestivum L.), and soybean (Glycine max (L.) Merr.) – were grown in strips one year and in perpendicular strips the following, with spring wheat planted a third year. Results were compared with those from two 10 x 10 sequence experiments on silt loam, glacial till-derived soil. Soil water depletion (SWD) and root growth were deeper in sandy loam soil than in silt loam. Under average precipitation, prior soybean enhanced spring wheat seed yield on sandy loam soil 14% above average, but prior spring wheat decremented it 14%. Under deficient precipitation, prior crop effects on spring wheat ranked in order of expected springtime soil water: dry pea, 11%; spring wheat, 4%; soybean, –5%; maize, –10%. Prior crops’ SWD largely determined spring soil water, with maize having greatest depletion. Excluding results from a year of low precipitation, prior crops’ effects on spring wheat yield on sandy loam soil were similar to results found at two sequence experiments on silt loam soil: dry pea – generally positive effect (N-production, water conservation); spring wheat – negative (disease); soybean – positive (N-production); maize – generally negative (heavier water use). Same year comparison of three crops (9 sequences) on sandy loam soil vs. silt loam showed average dry pea and spring wheat yields being equivalent. However, average maize yield was 37% lower on silt loam, with maize-after-maize yielding 54% less. No-till management and prior grass rendered productivity of the soils equivalent, and superior capacity of sandy loam site to conduct water and accept root growth lessened negative, water-generated sequence effects.