Deep drought

A low-fertility soil improver such as leaf mold can be incorporated as the bed is dug initially. This deep cultivation is useful where the soil is compacted. It results in a deep, fertile zone with an open, free-draining structure into which roots can easily penetrate. Medium- to high-fertility materials, if required, should only be mixed into the top 6-8 in (15-20 cm). Increases in yield are noticeable and plants cope better in drought. Make the edging at least 6 in (15 cm) high as the soil level will rise considerably. 

Fig. 9.4 Soil water content, leaf area, plant water stress, flammability and daily rainfall of mature forest, secondary forest and cattle pasture during the severe 1992 dry season. As deep soil water was depleted during this measurement period (a, b), severe drought stress developed in some trees of the mature forest (d), but the loss of green leaf area was lower in the mature forest than in the secondary forest and cattle pasture (c). Because of this capacity to retain leaves despite severe water stress, the mature forest is rarely susceptible to fire even during a severe dry season such as this (e). Plant-available soil water was measured from 0 to 2 m depth (a) and from 2 to 8 m depth (b) using Time Domain Reflectometry sensors imbedded in the walls of deep soil shafts (Nepstad et al. 1994, Jipp et al. 1998).

Water deeply and infrequently to encourage grasses to develop deep roots so they ll be more drought-tolerant. 

Zegada-Lizarazu, W., and M. lijima. 2005. Deep root penetration may help millet species to exploit soil water more efficiently and therefore overcome drought stress. Plant Production Science 8 454-460. 

Dug wells—Dug wells are the oldest type of well and date back many centuries they are dug by hand or by a variety of unspecialized equipment. They range in size from approximately 4 to 15 ft in diameter and are usually about 20 to 40 ft deep. Such wells are usually lined or cased with concrete or brick. Dug wells are prone to failure from drought or heavy pumpage. They are vulnerable to contamination and are not acceptable as a public water supply in many locations. 

Sherborne series. Shallow (less than 25 cm deep), reddish-brown, loam-textured soils of variable depth and stoniness (and so subject to drought). They are mainly found on the soft oolitic hmestones of the Cotswolds, and in parts of Northamptonshire, and the Cliff region of Lincolnshire. The soils of this series are moderately fertile, easy to manage and mainly grow cereals and grass. 

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