Cover crops used as killed mulch have been shown to decrease
evapotranspiration, in addition to acting as a barrier against weeds, and providing
a habitat for beneficial insects.� Using
cover crops could be especially beneficial in semi-arid New Mexico where water use is an ever decreasing
commodity.� In this study, six annual cover
crop varieties were evaluated in killed-mulch cropping systems in order to
measure the potential decrease in water use on chile pepper fields during the
growing season.� Additionally, the effect
of the killed mulch on weed and insect populations was determined.� Six cover crop cultivars were planted into 101.6
cm beds in a split-plot design, with crop cold-hardiness as the whole plot factor
and cover crop variety as the sub-plot factor.�
Each replication consists of three beds (60.39cm2), with a
total of three replications per cultivars. Three cold-sensitive cultivars crops
were planted in September 2005 and three cold-tolerant cultivars crops were
planted October 2005, with bare ground as the control.�� Irrigation for each treatment was accomplished
through subsurface irrigation and was quantified using water meters.� Chile
peppers (Capsicum annuum,
cv. �AZ-20') were transplanted into each bed during April 2006.� Data regarding irrigation scheduling, weed
densities, insect populations, and vegetable crop yield were taken from the
center row of each sub-plot.� Irrigation
schedules were established with soil moisture measurements at 20cm and 30cm
depth using Frequency Domain Reflectrometry (Diviner 2000�).� Weed densities were evaluated every two weeks
using a quadrat.� Insect populations were
monitored weekly by pit-fall traps and sticky traps.� Both the cold-sensitive and cold-tolerant
cover crops, the grass varieties established faster, at a greater density, and
with less water applied than the legume cover crop varieties.� This illustrates a greater potential benefit
of grass cover crops as part of a killed mulch system for water conservation
purposes.