Agriculture Reference
In-Depth Information
2010; Lal 2013; Powlson et al. 2013), and strengthen soil resilience and its disease-
suppressive attributes.
Therefore, the objectives of this chapter are to discuss the results of a long-
term soil management experiment on soil quality and agronomic productivity of
a Chernozem in Moldova. In addition, the results are discussed in the context of
sustainable management of these soils under similar ecological characteristics else-
where in Eastern Europe.
9.2 METHODS AND CONDITIONS
The long-term field experiments on a typical Chernozem (heavy clay) on the Balti
steppe in northern Moldova have been established for ~40-50 years. The surface
0-20 cm layer of these soils is characterized by an SOM concentration of 4.8%-5.0%
(by the Tiurin method); pH
water
7.3; pH
CaCl2
6.2; and concentration of total N, P, and K
of 0.20%-0.25%, 0.09%-0.11%, and 1.22%-1.28%, respectively. Details of soil prop-
erties and physiographic characteristics have been reported elsewhere (Dent 2013;
Krupenikov et al. 2011).
The long-term field experiment with crop rotation, established in 1962, includes
eight crop rotations with different intensities (40%-70%) of row crops. Winter wheat
(
T. aestivum
) is grown in three fields of each crop rotation (30%), but after differ-
ent preceding crops (early harvested—vetch [
Vicia sativa
] and oats [
Avena sativa
]
for green biomass; alfalfa [
Medicago sativa
] on the third year after first cutting,
etc.; corn for silage and corn for grains). Fertilization with organic and mineral
fertilizers is done according the recommended rates for the Republic of Moldova.
Simultaneously, several crops are grown as permanent crops. The size of the experi-
mental plots is 283 m
2
in crop rotations with three replicates. The size of the experi-
mental plots for permanent crops is 450 m
2
, but without any replications.
The long-term field experiment with four systems of fertilization includes
1. Unfertilized (absolute control)
2. Mineral fertilizer at three rates (NPK
75
, NPK
130
, and NPK
175
kg a.i. per hect-
are of crop rotation)
3. Organo-mineral fertilizer with two rates of FYM (10 and 15 Mg/ha) and
three rates of mineral fertilizers per hectare of crop rotation
4. Organic fertilizers (15 Mg of FYM) per 1 ha of crop rotation
The following mineral fertilizers are used in the experiment:
1. Ammonium nitrate (31.1%-35.0% a.i. of nitrogen)
2. Double superphosphate (45%-50% a.i. of P
2
O
5
)
3. Muriate of potassium (40% a.i. K
2
O)
4. Ammonium phosphate (11%-12% a.i. N and 46%-60% a.i. P
2
O
5
)
The composted farmyard cow manure used in the experiment contains C—13.2%,
N—0.51%, P—0.23%, and K—0.60% on a dry-weight basis.
