Bewertung landwirtschaftlicher Produktivitätspotentiale der globalen Landressource

Ziel unserer Arbeiten ist die Klassifikation und funktionelle Bewertung von Agrarstandorten nach einheitlichen Kriterien. Solche Informationen könnten für die überregional vergleichende Bewertung und standortgerechte nachhaltige agrarische Nutzung von Böden hilfreich sein. Wir untersuchten mehr als 100 repräsentative Böden auf Versuchsstandorten in bedeutenden Agrarregionen der Welt. Das sind Europa, Nordchina, die Prärieregionen Nordamerikas, sowie die Steppen Westsibiriens und Kasachstans. Die Böden wurden nach der World Reference Base for Soil Resources (WRB 2006) klassifiziert und mittels Müncheberger Soil Quality Rating (M-SQR) funktionell bewertet. Das indikatorbasierte M-SQR erwies sich als praktikabel und führte zu plausiblen Wertezahlen der Bodengüte. Die Bewertungskennziffern des M-SQR können je nach Landnutzungsintensität und Anpassungsgüte der Indikatoren etwa 50-80 % der Ertragsvariabilität von Getreide erklä¬ren. Es wird geschlußfolgert, daß das M-SQR für die skalenübergreifende Abschätzung von landwirtschaftlichen Produktivitätspotentialen, also als Basiswerkzeug für ein globales Bodenmonitoring, geeignet ist. Das M-SQR erweitert Bodenklassifikationssysteme wie die WRB 2006 um den Aspekt der Bodenfunktionalität

Thematic Issue on Soil Water Infiltration

International audienc

Effect of Previous Crop Roots on Soil Compaction in 2 Yr Rotations under a No-Tillage System

Compacted soils affect global crop productivity and environmental quality. A field study was conducted from 2014 to 2020 in the northern Great Plains, USA, to evaluate the effect of various rooting systems on soil compaction in 2 yr rotations of camelina (Camelina sativa L.), carinata (Brassica carinata A.) and a cover crop mix planted in place of fallow with durum (Triticum durum D.). The study was designed as a randomized complete block with three replications in a no-tillage system. The soil was classified as Dooley sandy loam (fine-loamy, mixed, superactive, frigid Typic Argiustolls) derived from glacial till parent material. Three measurements of soil penetration resistance (PR) were taken with a penetrometer to a depth of 0–30 cm within each plot. Soil moisture contents were determined using a TDR sensor at the time of PR measurements. Both measurements were monitored prior to planting in spring and after harvest. Initial PR results from spring 2014 showed that all plots had an average of 2.244 MPa between the 8–20 cm depth, due to a history of tillage and wheel traffic caused by various field activities. Covariance analysis indicated that soil PR was not significantly affected by crop type and moisture content. After one cycle of the 2 yr rotation, the 2016 measurements indicated that the compacted layer existed at the same initial depths. However, after two and three cycles, soil PR values were reduced to 1.480, 1.812, 1.775, 1.645 MPa in spring 2018 and 1.568, 1.581, 1.476, 1.458 MPa in 2020 under camelina, carinata, cover crop mix, and durum treatments, respectively. These findings indicate that previous cover crop roots could effectively improve soil compaction by penetrating the compacted layer, decompose over time and form voids and root channels. Although these results are novel and significant, further research is needed on different soils and under cover crops with different root systems to support our findings prior to making any conclusion

Does Increasing the Diversity of Small Grain Cropping Systems Improve Aggregate Stability and Soil Hydraulic Properties?

Wheat (Triticum aestivium L.) and barley (Hordeum vulgare L.) are two commonly grown cereal crops in the northern Great Plains. Adding other crops such as field pea (Pisum Sativum L.), canola (Brassica napus L.), or camelina (Camelina sativa L.) to wheat or barley cropping systems may improve soil quality. However, little is known about the effects of including oilseeds in small grain cropping systems on soil physical properties. We sampled an 8-year dryland study with 10 different cropping systems including continuous spring wheat, continuous winter wheat, continuous barley, pea–spring wheat, pea–barley, pea–winter wheat, pea–barley–camelina–spring wheat, pea–barley–canola–spring wheat, pea–winter wheat–camelina–spring wheat and pea–winter wheat–canola–spring wheat. We measured dry aggregate stability, wet aggregate stability, water retention, hydraulic conductivity, bulk density and total carbon. Continuous barley and winter wheat had a higher fraction of large dry soil aggregates, whereas the pea–barley–canola–spring wheat and pea–spring wheat cropping systems had a higher fraction of small aggregates in the 0–15 cm depth. However, wet aggregate stability, water retention, bulk density, hydraulic conductivity and soil carbon concentration were not affected by the cropping system in the 0–15 cm depth. Diversifying small grain cropping systems by adding canola or camelina oil seeds and peas generally did not affect soil physical properties at this location