More Is not ALWAYs better WIth GrAPevInes
To establish healthy grapevines a good soil is needed in the early years. But the best wines general y come from soils that are not overly fertile and al ow for some water stress during the season. High organic matter and nitrogen contents in vineyard soils create overly abundant vegetative growth in grapevines, reducing fruit set and requiring repeated pruning. Also, important traits of wines are enhanced by the presence of the grapes’ anthocyanin pigments, which contribute to both the taste and the color of wine. Mild water stress and reduced root growth during the early summer (between bloom and the beginning of the ripening stage) increase the content of these pigments. Poor drainage and aeration are bad for wine quality. Some of the world’s best wines are grown on soils that al ow for deep rooting; are calcareous, sandy, or gravelly; and are low in organic matter. The best climates experience water deficits during the growing season, which can be supplemented by irrigation if needed. This complex interaction between soil, climate, and vine is referred to as terroir.
operations or swap land with them in a rotation. Farms
and allelopathically control weeds, but it requires a long
near urban areas may benefit from leaves and grass
time window for sufficient growth.
clippings and municipal or food waste composts, which
The need to harvest crops during a very short period
are increasingly becoming available. In such cases, care
before quality declines regardless of soil conditions often
should be taken to ensure that the compost does not
results in severe compaction problems on large vegeta-
contain contaminants.
ble farms using large-scale equipment. Controlled-traffic
Vegetable cropping systems are often well adapted to
systems, including permanent beds, should be given
the use of cover crops because the main cropping season
serious consideration. Limiting compaction to narrow
is generally shorter than those for grain and forage
lanes and using other soil-building practices between
crops. There is usually sufficient time for the growth of
them is the best way to avoid compaction damage under
cover crops in the pre-, mid-, or post-season to gain real
those conditions.
benefits, even in colder climates. Based on identified soil
health constraints (see table 23.2) and growth win-
Fruit Farms
dows, vegetable growers often have a multitude of cover
Many fruit crops, such as bramble, citrus, grape, and
cropping options. Using the cover crop as a mulch (or
stone fruits, are perennials that take several years to
importing mulch materials from off the farm) appears
establish and may be harvested for twenty or more
to be a good system for certain fresh market vegetables,
years. This means that mistakes made during the
as it keeps the crop from direct contact with the ground,
establishment years can have negative impacts on future
thereby reducing the potential for rot or disease.
years and places the emphasis on addressing soil health
But many vegetable crops are highly susceptible to
concerns in the establishment phase. Comprehensive
diseases, and selection of the right cover or rotation
soil health analyses and field surveys are worthwhile
crop is critical. For example, according to Cornell plant
investments, considering the expense of establishing
pathologist George Abawi, bean root rot is suppressed
orchards and vineyards. For tree and vine crops, the
by rapeseed crown vetch, wheat, and rye but is actually
reconnaissance should pay attention to deeper soil lay-
enhanced by white clover. Sudan grass can effectively
ers, especially the presence of hard pans, acidity, and
remediate compaction, control pathogenic nematodes,
shallow water tables, because the quality of the fruits is
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Building SoilS for Better CropS: SuStainaBle Soil ManageMent