Root development in potato and carrot crops – influences of soil compaction

Abstract

Row crops such as potatoes (Solanum tuberosum L.) and carrots (Daucus carota L.) are of high economic value in the Nordic countries. Their production is becoming more and more specialized, including continuous arable cropping and heavier farm machinery, with increased risk of soil compaction. The result may be restricted root development and economic losses. Potatoes have widely branched adventitious roots, whereas carrots have taproots with fibrous roots extending from them. Under optimal soil conditions, total root length per surface area may reach more than 10 km m −2 for both species. Maximal root depth is about 140 cm for potato and more than 200 cm in carrots. Most of the root mass is usually distributed within the upper 100 cm, whereof more than 50% may be deeper than 30 cm. Soil compaction causes a dense soil with few large pores, poor drainage and reduced aeration, especially in wet soils with low organic matter content and high proportions of silt or clay. With compacted subsoil layers, roots will be concentrated more in the upper layers and thus explore a smaller soil volume. This will lead to reduced water and nutrient uptake, reduced yields and low nutrient utilization efficiency. In this review article, we describe the interactions between root development and soil conditions for potatoes and carrots, with special focus on sub-optimal conditions caused by soil compaction. We also discuss the effects of tilling strategies, organic material, irrigation and fertilization strategies and controlled traffic systems on root and yield development. To reduce subsoil compaction there is a need to implement practises such as controlled traffic farming, new techniques for ploughing, better timing of soil operations, crop rotations with more perennial crops and supplements of organic material. Moreover, there is a need for a stronger focus on the impacts of farm machinery dimensions.

Food losses and waste in primary production

“…We found no P-values under 0.21. Headland with increased soil compaction and other unfavourable conditions will give uneven yields (Johansen et al 2015). A field survey yield sample will normal have a net yield that is 25-35% lower after correcting for areas with lower yield.…”

Soil compaction problems and subsoiling effects on potato crops: A review

“…Controlled traffic farming (CTF) is being adopted internationally to reduce soil compaction due to the heavy wheel loads of modern farm equipment (Johansen, Thomsen, Loes, & Riley, 2015). Controlled traffic farming establishes and maintains the same traffic lanes for equipment to ensure minimal changes due to wheel‐traffic compaction on most of the cultivated area (Wolkwski & Lowery, 2008).…”

“…Farm implements for different cultivation practices can be of different widths, which results in low interest by farmers to adopt this method. For all working machine operations, the cost of CTF may comprise about 30% of the total production cost (Johansen et al., 2015). These expenses are why CTF is still only being recommended for small arable farms for seed potato, tulip ( Tulipa L.), onion ( Allium cepa L.), and others.…”

Evaluation of deep tillage remediation in a construction easement on soil compaction and crop yield

“…Root development in soil requires a continuous network of appropriately sized pores (Tracey et al, 2011). In heavily compacted soils, root penetration is restricted, due to the increase in soil strength, and therefore, roots explore weaker soil (Johansen et al, 2014). Taylor and Gardner (1963) found that cotton roots penetration were excessively restricted when the soil penetration resistance of measured 3.0 MPa and above.…”

“…Although soil compaction can be alleviated by tillage practices, soil physical properties, such as air porosity, infiltration rate, and soil strength, can still be affected by soil compaction for up to a decade (Abu-Hamdeh, 2003;Johansen et al, 2014). A study on the effects of deep tillage on reclaimed mined land concluded that treatment enhances the infiltration only for a short time (Chong, 1996).…”