The effects of crop rotations and fertilization on wheat productivity in the pampean semiarid region of Argentina. 1. Soil physical and chemical properties
Wheat in the semiarid region
of Argentina has often been grown as a low-input crop. Rainfall scarcity and
distribution are the main characteristics of this region. The knowledge of the
combined effects of crop rotation and fertilization on soil physical and
chemical properties are the key for a sustainable crop production. Soil
properties for an Entic Haplustoll in the semiarid region of Argentina were
evaluated, where different crop rotations were used for 15 years. Wheat-wheat
(Triticum aestivum L.) (WW), wheat-grazing natural grasses (WG) and wheat-legume
[vetch (Vicia sativa L.) plus oat (Avena sativa L.) or Triticale (Triticum
aestivum L. Secale cereale L.)] (WL)
rotations with and without fertilizer (64 kg N and 16 kg P ha-1) were
studied. The annual wheat cropping system (WW) resulted in the lowest soil
organic carbon (SOC) and total nitrogen (Nt) levels. Extractable phosphorus
(Pext) values were sufficient for wheat growth with all treatments and
decreased with depth. Fertilizer applications significantly increased the
proportion of large pores (>8.81 mm) in the 0±0.07 m depth of the WW and WG
system plots. A decrease in the proportion of medium size pores (0.19-8.81 mm)
and in the water holding capacity was observed in the WG rotation plots. The
fertilized treatments resulted in the following sequence of available water: WL
> WW > WG. Bulk density was similar with all treatments for each depth,
except with the fertilized WG treatment that had the lowest value in the 0-0.07
m depth. These results showed the positive influence of legume inclusion (WL)
and alternate cattle grazing (WG) on SOC and Nt contents.
Miglierina A.M., J.O. Iglesias, M.R. Landriscini, J.A.
Galantini, R.A. Rosell. 2000. The effects of crop rotations and fertilization
on wheat productivity in the pampean semiarid region of Argentina. 1. Soil
physical and chemical properties. Soil &
Tillage Research 53: 129-135.
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