Effects of soil compaction in potato (Solanum tuberosum) crops

Abstract

SUMMARYSince many soils used for growing potatoes in the UK are likely to be close to their plastic limit for cultivation during early spring, there exists the potential for soil compaction to occur during planting which will restrict root penetration. A series of experiments showed that soil compaction delayed emergence, reduced rate of leaf appearance and ground cover expansion, shortened canopy cover duration and restricted light interception, which combined to reduce tuber yield. Rooting density and maximum depth of rooting were reduced, particularly where compaction was shallow. In some soils, irrigation helped alleviate some of the effects of compaction but in others it exacerbated their severity. Using a cone penetrometer, relationships between rate of root penetration and soil resistance (Ω) were established from a number of experiments and replicated blocks in commercial fields and an overall relationship of the form y=16·3–4·08Ω mm/day was produced. Root penetration rates of c. 20 mm/day were measured in the intensively-cultivated ridge zone but growth rates were halved at a Ω of 1·5 MPa. A survey of 602 commercial fields showed that two thirds of fields had Ωs ⩾3 MPa (where root growth rates would be <2 mm/day) within the top 0·55 m of the soil profile. Thus, rooting depth is likely to be considerably shallower than desirable and lead to inefficiency of water and nutrient utilization. The use of powered cultivators to separate stones and clods from beds or ridges and produce a fine seedbed is now almost universally adopted in the UK. However, the system is both time and energy inefficient and increases the risk of creating soil compaction, particularly at shallow depths. All cultivation equipment has been shown to cause compaction and it is suggested that the consequences of the shortening of the growing season from delaying planting by a few days to allow the soil to dry are far less than the yield and quality losses caused by compaction.

Depth to compact subsoil effects on soil properties and barley–potato yields on a loamy soil in New Brunswick

“…The effects of compaction and resulting water stress will differ in shallow-rooted and deep-rooted crops ; thus, a deep-rooted crop like alfalfa may respond differently. Lower yields from our shallow treatment may have been caused by shallower available rooting depth, which would lead to inefficiencies in water and nutrient utilization (Stalham et al 2007). Ross (1986) found that subsoiling increased potato yields under very droughty conditions, but had no effects under near optimum water conditions.…”

“…25), when the shallow treatment had 4% emergence compared with 9% for the medium and 8% for the deep. Stalham et al (2007) reported delayed emergence in potato as a result of planting compaction in the United Kingdom. In our study, regardless of soil depth to the compact layer, all treatments had similar emergence by JD 190 (Jul.…”

Soil properties and agronomic attributes of potato grown under deep tillage in succession of grass species

“…These factors combined have impaired tuber yield (Stalham et al, 2007). In that research, density of roots and the depth achieved by them were significantly reduced by compaction, especially in areas wherein compaction occurred in more superficial layers (e.g.…”

“…The most superficial layer evaluated (0-20 cm) showed no difference for any of the comparisons between treatments, confirming the efficacy of CT for this depth. When considering 1.5 MPa as a reference (Stalham et al, 2007), no limitation for the potato root growth occurred up to 20 cm depth for all treatments. Nevertheless, only DT treatments presented no limiting penetration resistance at 20-40 cm.…”

“…The subsoil compaction directly affects potato root growth due to mechanical resistance to penetration ; Henrique P Guerra 1 ; Carlos F Ragassi (Stalham et al, 2007). A shallow root system limits the ability of the plant to uptake nutrients as well as the resistance to periods of water stress.…”