ARS | Publication request: TILLAGE AND COMPOST EFFECTS ON CORN GROWTH, NUTRIENT ACCUMULATION, AND GRAIN YIELD

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 18, 2006
Publication Date: January 1, 2007
Citation: Singer, J.W., Logsdon, S.D., Meek, D.W. 2007. Tillage and compost effects on corn growth, nutrient accumulation, and grain yield. Agronomy Journal. 99(1):80-87.

Interpretive Summary: Applying organic amendments to cropland affects corn response differently to tillage systems. Identifying causes of this differential response could match amendment inputs to responsive tillage systems. The objectives of this research were to determine if dry matter production and nutrient uptake could explain the different response for corn grain yield. A corn-soybean-wheat/clover rotation was initiated in 1998 in plots that had been managed with moldboard plow, chisel plow, or no-tillage since 1988. Compost provided a neutral (2 yr) or negative benefit (1 yr) to corn yield in moldboard plow. Compost provided no benefit to corn yield in chisel tillage. Corn in no-tillage derived a neutral (2 yr) or positive (1 yr) effect on grain yield from compost amendment. The tillage and compost responses observed in this study cannot be explained by plant nitrogen status or dry matter partitioning. Sequential compost application can reduce inorganic nitrogen inputs for corn production, but must be balanced to avoid excessive soil phosphorus accumulation. Grain yield from soil managed using no-tillage may respond to compost amendment, although yields may still be lower than soil managed using moldboard plow and compost. Consequently, farmers applying compost in a similar rotation and landscape should consider using no-tillage if profitability is greater than conventional tillage. This research benefits producers by providing information on more effective soil management practices.

Technical Abstract: Applying organic amendments to cropland affects corn response differently to tillage systems. Identifying causes of the tillage by amendment interaction could match amendment inputs to responsive tillage systems. The objectives of this research were to determine if shoot dry matter (DM), nutrient uptake, and leaf gas exchange could explain the tillage by compost interaction for corn (Zea mays L.) grain yield. A corn-soybean [Glycine max (L.) Merr.]-wheat (Triticum aestivum L.)/clover (Trifolium spp.) rotation, in all phases, was initiated in 1998 in plots that had been managed with moldboard plow (MP), chisel plow (CT), or no-tillage (NT) since 1988. Compost amendment increased whole-plant P and K uptake 19 and 21%, averaged across 2 yr. No-tillage increased whole-plant P uptake 1 yr compared to MP and CT (113 vs 65 kg ha-1) and increased grain P concentration (3.1 vs 1.5 g kg-1). Compost provided a neutral (2 yr) or negative benefit (1 yr) to corn yield in MP. Compost provided no benefit to corn yield in CT. Corn growing in NT derived a neutral (2 yr) or positive (1 yr, 9%) effect on grain yield from compost amendment. The tillage and compost responses observed in this study cannot be explained by plant N, soil water use, leaf gas exchange, or DM partitioning. Sequential compost application can reduce inorganic N inputs for corn production, but must be balanced to avoid excessive soil P accumulation. Grain yield from soil managed using NT may respond to compost amendment, but reasons for this response remain unclear.