Effects of crop rotation and management system on water-extractable organic matter concentration, structure, and bioavailability in a chernozemic agricultural soil

Crop Domestication, Root Trait Syndromes, and Soil Nutrient Acquisition in Organic Agroecosystems: A Systematic Review

Selecting crops that express certain reproductive, leaf, and root traits has formed detectable, albeit diverse, crop domestication syndromes. However, scientific and informal on-farm research has primarily focused on understanding and managing linkages between only certain domestication traits and yield. There is strong evidence suggesting that functional traits can be used to hypothesize and detect trade-offs, constraints, and synergies among crop yield and other aspects of crop biology and agroecosystem function. Comparisons in the functional traits of crops vs. wild plants has emerged as a critical avenue that has helped inform a better understanding of how plant domestication has reshaped relationships among yield and traits. For instance, recent research has shown domestication has led important economic crops to express extreme functional trait values among plants globally, with potentially major implications for yield stability, nutrient acquisition strategies, and the success of ecological nutrient management. Here, we present an evidence synthesis of domestication effects on crop root functional traits, and their hypothesized impact on nutrient acquisition strategies in organic and low input agroecosystems. Drawing on global trait databases and published datasets, we show detectable shifts in root trait strategies with domestication. Relationships between domestication syndromes in root traits and nutrient acquisition strategies in low input systems underscores the need for a shift in breeding paradigms for organic agriculture. This is increasingly important given efforts to achieve Sustainable Development Goal (SDG) targets of Zero Hunger via resilient agriculture practices such as ecological nutrient management and maintenance of genetic diversity.

Nutrient and sediment losses in snowmelt runoff from perennial forage and annual cropland in the canadian prairies

An 8-yr field-scale study, 2005 to 2012, investigated effects of agricultural land use on nutrient and sediment losses during snowmelt runoff from four treatment fields in southern Manitoba. In 2005, two fields with a long-term history of annual crop (AC) production were planted to perennial forage (PF), while two other fields were left in AC production. In 2009, the AC fields were converted to PF, while the PF fields were returned to AC. Runoff flow rates were monitored at the lower edge of the fields, and nutrient concentrations of runoff water were determined. The effects of AC and PF on selected variables were similar for the spatial (between-fields) and temporal (within-field) comparisons. The flow-weighted mean concentrations (FWMCs) and loads of particulate N, P, and sediment were not affected by treatment. Soil test N and the FWMC and load of NO (NO + NO) were significantly greater in the AC treatment, but the FWMC and load of NH were greater in the PF treatment. Loads of total dissolved N (TDN) and total N (TN) were not affected by treatment, although the concentrations of TDN and TN were greater in the AC treatment. The PF treatment significantly increased FWMCs and loads of total dissolved P (TDP) and total P (TP). On an annual snowmelt runoff basis, the PF treatment increased the FWMC of TDP by 53% and TP by 52% and increased the load of TDP by 221% and TP by 160% compared with the AC treatment. The greater P and NH losses in the PF treatment were attributed mainly to nutrient release from forage residue due to freezing.