Long-Term Winter Wheat Cropping Influence on Soil Quality ... 63short-straw varieties were introduced. Kuznová and Hejcman (2009)
summarizing 50 years’ results in the Czech Republic reported that the variety
had the largest effect on grain yield followed by mineral fertilizers, the
preceding crop and farmyard manure application. Evaluation of long-term data
indicates that the most favorable period for wheat production in the Southern
Pannonian Basin occurred from 1980 to 1990 (Table 1) under intensified
production technology (i.e. efficient weed and pest control and proper mineral
fertilization). Starčević et al., (2003) found that the rate of winter wheat yield
increase was 136 kg ha-^1 year-^1 (1961-70), 99 kg ha-^1 year-^1 (1971-80), and 76
kg ha-^1 year-^1 (19 81 - 90). However, from 1991 to 2000, a considerable yield
decline of 120 kg ha-^1 year-^1 and fluctuations were observed in response a
lower input, reduced cropping technology and unfavorable climatic conditions,
though high-yielding varieties were continuously grown (Denčić et al., 2009).
Generally, during the first decade of the 21st century, average winter wheat
yields in the Southern Pannonian Basin was approximately 4 t ha-^1 , which
could be attributed to continuation of the lower production inputs, unfavorable
weather condition during vegetation, and change in soil physical and chemical
properties (Starčević et al., 2003). The evaluation of average production
variability index (APV) showed that the yield variability in the first decade of
21 century is similar to the period of 1960/70. The long-term yield data
analyses have led to the conclusion that yield level does not increase
respectively to production input and it appears that common cropping
management for winter wheat was inadequate for higher yield formation. This
could be also ascribed to the cumulated impact in a climatic condition
discrepancy that became noticeable in the first decade of 21st century.
Likewise, the winter wheat cropland area decreased over the observed period,
partly due to lower demand, higher winter wheat yields and greater area
allocated for the production of industrial crops (soybean, sunflower and sugar
beet).
Similar trends of winter wheat yields were observed in other countries
while the wheat-producing areas of these regions remained virtually
unchanged in the last decade of the 20th century (Calderini and Slafer, 1998;
Braun et al., 2008), and stagnating yield growth has become a concern
worldwide (Reynolds et al., 2007).
With respect to cultivated area and beneficial effects of its cropping,
winter wheat is considered as one of the most underestimated crop in the
modern agriculture. In line with this is farmer perception on winter wheat
growing. Most farmers have lower economic expectation from the winter
wheat growing and therefore they assess winter wheat role in the prevention of