engleski

The influence of different soil tillages for maize on soil compaction in Croatian Baranja region

Conventional tillage for the maize in eastern Croatia has been based on ploughing, because maintaining of high grain yield has been concerned of the biggest importance. But, ploughing needs powerful energy aggregates, which cause strong soil compaction by large and heavy machines. On that way soil physical properties can be seriously disturbed, which can be reflected on soil chemical and biological properties, too. Therefore, searching for tillage which is able to maintain both, high yield and lower soil disturbance, has been recognised as a highly interesting topic for this research. "Kneževo" experimental site has been established in Croatian Baranja region as a monofactorial trial, with randomised plots in blocks within four replications, and with basic plot area of 720 m2 (18x40 m). in 1998, as a stationary experiment on Chernosem soil type which is the dominant soil type of "Kneževo" farm, "Belje IPK" agricultural enterprise. The maize hybrid OSSK 444 (created by The Agricultural Institute Osijek) has been sown after picking forage maize in 1999, with the next soil tillage treatments: 1) Standard, conventional soil tillage based on ploughing (30-35 cm) and diskharrowing, then classical sowing ; 2) Only diskharrowing and seed-bed preparation followed by sowing, like at var. 1 ; 3) Diskharrowing combined by loosening of chisel ploughing (by subsoiler chisels up to 30 cm deep, 40 cm spacing between chisels ; 4) Only rough diskharrowing, without fine seed-bed preparation, and sowing by No-till planter John Deere "Maxemerge" and 5) Direct sowing by No- till planter John Deere "Maxemerge". The soil resistance has been sampled by mechanical cone-penetrometer with spring on five different depths (5, 10, 15, 20 and 25 cm) per each plot. The undisturbed soil samples have been taken at two depths (7-12 and 20-25 cm). Both samplings were carried out during July 1999. The Standard tillage (var.1) showed out soil resistance average of 402 kPa, which was highly significant in comparison with var. 5 (801 kPa), and significantly stronger than var. 4 (583 kPa). There were no significant differences between Standard and var. 2 and 3 (554 and 349 kPa, respectively). Different results have been shown on bulk density averages, where was no significant difference between var. 1 (1.45 g cm-3) and other variants (1.42, 1.43, 1.48 and 1.54 g cm-3, for var. 2, 3, 4 and 5, respectively). Porosity averages had similar relationships among treatments (Pvar.1 = 45.7, Pvar.2 = 47.5, Pvar.3 = 47.1, Pvar.4 = 44.8, and Pvar.5 = 43.0 %). Nevertheless, advantageous weather conditions produced exceptional grain yields (10.53, 10.65, 10.45, 10.42 and 9.62 for variants 1, 3, 2, 4 and 5, respectively), where significant difference was recorded only between var. 5 and all other tillage variants.

standard conventional tillage ; diskharrowing ; diskharrowing and chisel ploughing ; soil resistance ; soil water holding capacity ; porosity

nije evidentirano