Joint International Conference on Long-term Experiments ...

Tops soil (0-30 cm) samples were taken from fields with an average size of 1.0 ha. They
were representative for the following classes of soil: luvisoil, clay illuvial brown, clay
illuvial chernozem. Each type of soil was fertilized as follows: N100, P 70, mineral NPK
(N100 P70 K60) mineral and organic NPK (N100 P70 K60 + 20t ha -1 farmyard) and lime
addition at various rates: 0.5 and 10 t ha -1
Detailed land use and agricultural management data were collected through
Romanian Statistic Annual (2004-2005). Each field was considered as a separate unit
because it is not managed in a coherent rotation.
In 2006 five representative points of each type of soil were selected for sampling. The
soils were air dried and ground ≤ 2mm sieve at the time of sampling.
Extractions with acetate-lactate solution (AL) were performed using soil to
solution ratio of 1:20 and the shaking time was 30 minutes. 5ml filtrate was treated with
(NH4)2 MoO4 0,15% and 5 ml fresh prepared 1,5% ascorbic acid standard curve was
prepared using suitable volumes of standard solution in place of sample. It has been
used a series of 6 standard solutions within the approximate range of 0.01 – 2.0 mg P/l.
After 10 minutes absorbance was measured at 880 nm using a reagent blank as a
reference solution.
Soil pH was measured in water using 1:2.5 ratio.
All analyses were carried out in 4 repetitions.
RESULTS AND DISCUSSIONS
1. Chemical analysis of soils showed that the pH and mobile phosphorus content was
exactly related to lime ratio and type of fertilizer. Impact of treatment (liming and
fertilizing) on different types of soil is shown in the below tables:
1. ALBIC LUVISOIL (initial pH = 4.90, P=15.4 ppm)
In this experiment the strongest effect on improving soil acidity and phosphorus content
of albic luvisoil was observed when fertilizing with mineral and organic manure
mixture (N100 P 70 K60 + 20t/ ha -1 FYM) and applying 10t ha -1 limestone.
On the background without organic fertilizer the greatest efficacy was recorded when
albic luvisoil had been applied with N100 P 70 K60 and 10t / ha -1
Table 1: Effect fertilizing and liming 5t/ ha -1 CaCO3 on albic luvisoil
Treatment ∆pH P (ppm)
Control 0.49 21.5
N100 0.21 10.1
P70 0.47 28.0
N100 P70 K60 0.96 40.1
N100 P 70 K60 + FYM 0.89 46.5
FYM 0.35 40.0
∆pH = pH variation
FYM = farmyard manure
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