INVESTIGADORES
DIAZ ZORITA Martin
artículos
Título:
Soil structural disturbance effects on crop yields and soil properties in a no-till production system
Autor/es:
DÍAZ-ZORITA, MARTÍN; GROVE, JOHN H; MURDOCK, L; HERBEK, J; PERFECT, EDD
Revista:
AGRONOMY JOURNAL
Editorial:
American Society of Agronomy
Referencias:
Lugar: Madison, WI; Año: 2004 vol. 96 p. 1651 - 1659
ISSN:
0002-1962
Resumen:
The development of well-structured soils is a goal for achieving
sustainable and productive agricultural systems. Nevertheless, the
maintenance of soil structure in continuous no-till (NT) soils has
sometimes been thought to induce soil conditions that are detrimental
to crop yields. The objectives of this research were to characterize
the effects of periodic tillage disruption in otherwise NT systems on
soil properties and the yields of winter wheat (Triticum aestivum L.),
double-cropped soybean [Glycine max (L.) Merr.], and maize (Zea
mays L.) in rotation and to determine if soil structural changes oc-
curring in tilled soils are independent of changes in other soil proper-
ties. A field experiment was established in 1992 on a Huntington
silt loam soil (Fluventic Hapludoll) at the University of Kentucky
Research and Education Center in Princeton (KY) under a NT crop
sequence with two seedbed preparation methods for winter wheat,
(a) NT or (b) chisel plus disk tillage (Till). In fall 2000, similar soil chemical
properties were observed between disrupted and continuous
NT systems over the 0- to 20-cm layer. The geometric mean diameter
of dry fragments and the soil water content retained between 0.0003
and 0.03 MPa water potential was greater in NT soils than in soils
tilled for winter wheat. Tillage for winter wheat enhanced winter
wheat yields (4.2% increase), mostly under low-yielding conditions,
but it resulted in a reduction of subsequent summer crop yields (i.e.,
3.7% for soybean and 7.0% for maize). The yields obtained in our
study translate to an economic benefit for the continuous NT system.
Net returns per hectare were estimated to be $73 higher for the winter
wheat/double-crop soybeanmaize rotation under NT than under Till
treatments. The differences in maize yields between NT and tilled
treatments were attributed to a better water supply in NT soil due
to the maintenance of a larger number of mesopores and a great
hydraulic conductivity. In the absence of significant changes in other
physicochemical properties, periodic tillage appears to disrupt soil
structure, which negatively affects crop productivity.