In order to enhance the adaptability and yield stability of maize, the effect of nutrient supply and plant density on yield was studied on a calcareous chernozem soil in Debrecen, while the relationship between sowing date and the grain moisture content at harvest was investigated on a typical meadow soil in Hajdúböszörmény. In the plant density experiment, the plant densities applied were 45, 60, 75 and 90 thousand plants/ha. The optimal fertilizer rates for the maize hybrids were: N 40-120, P2O5 25-75, K2O 30-90 kg ha-1. The application of NPK fertilizers in a wet year increased the yield by 40-50%. Hybrids with good chilling resistance at germination can be sown as early as 10 April, when the soil temperature reaches 8-10°C. There was a significant correlation between sowing date and the grain moisture content at harvest. When hybrids with good chilling resistance at germination were sown early, the grain moisture content at harvest was reduced by 5-10%. A plant density higher than the optimum reduces yield and yield stability. The optimal plant densities determined in the experiment were 60, 75 and 90 thousand plants/ha for two, three and one hybrid, respectively.
Different long-term experiments were carried on chernozem (Debrecen) and loamy (Hajdúböszörmény) soils. They included the most important agrotechnical, biological (hybrid) and agroecological (crop year, soil) factors in maize production. This paper evaluated the results of polyfactorial long-term experiments. For the maize the most favourable crop rotation was winter wheat (in a tri-culture) with an N 60–120, P2O5 60–70, K2O and 90–110 kg ha−1, and a density of 75–90,000 plants ha−1. The different input levels of maize crop management systems can modify an adaptive capacity to ecological conditions and the resilience of agro-ecosystems. The optimalization of agrotechnical elements reduces the harmful climatic effects. The yields of maize varied between 2–11 t ha−1 in extensive and 10–15 t ha−1 in intensive crop management systems, respectively.
Authors:M. Marković, P. Pepó, M. Sárvári, V. Kovačević, J. Šoštarić and M. Josipović
In the decade from 2000 to 2009, the yield of maize grain in Croatia varied from 4.2 t ha−1 (2003) to 8.0 t ha−1 (2008). The yield variation was mainly caused by weather conditions unfavourable for maize production, meaning lack of precipitation, unevenly distributed during the vegetation season, and mean air temperatures above the long-term mean. Irrigation has become a justified and essential agrotechnical measure that minimizes the damage caused by water deficit during critical plant growth stages and ensures high yields with good quality. In this paper two vegetation seasons (2006 and 2007) with quite different weather conditions for maize production were analysed in order to examine the importance of irrigation in terms of yield increase, irrigation water use efficiency (IWUE), irrigation efficiency (IE) and irrigation water use index (IWUI) in years favourable (2006) or too dry (2007) for maize production. The yield surpluses achieved with irrigation ranged from 8.54 t ha−1 to 9.62 t ha−1 in the average crop year (2006) and from 8.43 t ha−1 to 10.7 t ha−1 in the dry year (2007), depending on the irrigation method. In the dry year the values of IWUE where higher than in the average year (6.16 and 13.75 kg ha−1/mm, respectively, averaged over the hybrids).