Mechanical processing of whole crop barley before ensiling may be useful for improving nutrient use by dairy cattle.
And strategic crop rotations and nitrogen-fixing cover crops can also improve nutrient use efficiency, while limiting erosion and increasing soil carbon sequestration.
Examples that Denison specifically discusses (Chapter 5) with regard to the challenges of genetic engineering new traits in crop species include improving nutrient use and water use efficiency.
Free-living, biofilm-forming and root-colonizing rhizobacteria have therefore been considered as possible inoculants for increasing plant productivity and improving nutrient-use efficiency [ 4, 5].
From a management standpoint, increases in AOPD and yield were feasible since maize producers specialized, i.e., moved from low to better yielding fields, and intensified production, i.e., adopted best management practices (BMPs) such as better hybrids, use of irrigation, improved nutrient fertilization, weed control, and other options in favorable environments35.
In addition to increasing total nutrient content, pyrolysis improved nutrient availability, exception for nitrogen and iron.
However, unlike the improvements in nutrient adequacy for the shortfall nutrients, higher intakes of the other nutrients did not always translate into significantly improved nutrient adequacy.
In recent decades, numerous approaches (improved photosynthesis, nutrient use efficiency, tolerance to biotic and abiotic stress) have been proposed to increase grain yield per unit area (Bertin and Gallais 2001; Tuberosa et al. 2002; Hund et al. 2004; Grance et al. 1987; Louwerse and Zweerde 1997).
Therefore, the identification and molecular characterization of quantitative trait loci (QTL) and marker-assisted backcrossing of genes that regulate root traits that improve nutrient uptake and use efficiencies into modern varieties is of the highest importance.
