Do Cover Crop And Soil-Mediated Legacy Influence Succeeding Wheat Production?

ABSTRACT

Biotic interaction of cover crops (CCs) can have a legacy effect on succeeding crops mediated by changes in nutrient dynamics. Depending on species, CCs influence nitrogen (N) dynamics by sequestering N and subsequent N release. Interactions of three CC species, Austrian Pea (Pisum sativum L.), winter rye (Secale cereal L.), and winter camelina (Camelina sativa L.), and three different soils were studied under greenhouse conditions on wheat (Triticum aestivum L.) grain yield and soil N availability. CCs were grown for two months and then incorporated, followed by the planting of wheat. CC biomass production ranged from 0.10 to 2.05 Mg ha⁻¹ in this order by species: Pea> Rye> Camelina. Biomass production by soil was in the order of Casselton>Ada>Minot. Succeeding wheat grain yield and grain N uptake was highest under pea in the order of pea>camelina>control>rye. Rye reduced grain yield and N uptake. Wheat yield ranged from 2.19 to 3.24 Mg ha⁻¹ depending on CC species-soil interaction. The N balance showed a 3–79% higher N surplus with the CCs. The N balance ranged from 78 kg N ha⁻¹ for the control to 140 kg N ha⁻¹ for pea. N surplus was greater for a pea in all soils, indicating pea can be regarded as an effective cover that can efficiently recycle N and provide additional agronomic benefits. Greater N balance with CCs shows that CCs can increase the amount of N accounted for in the system, which can significantly affect the N dynamics throughout the growing season.

KEYWORDS:

• Cover Cropping
• Nbalance
• Ninput
• Noutput

Acknowledgments

The author wishes to acknowledge the excellent support provided by Norman Cattanach, for the greenhouse set up, collection, and processing of soil samples.