The effect and interaction of crop production factors on maize yield has been examined for nearly 40 years at the Látókép Experiment Site of the University of Debrecen in a long-term field experiment that is unique and acknowledged in Europe. The research aim is to evaluate the effect of fertilisation, tillage, genotype, sowing, plant densit...y, crop protection and irrigation. The analysis of the database of the examined period makes it possible to evaluate maize yield, as well as the effect of crop production factors and crop year, as well as the interaction between these factors.
Based on the different tillage methods, it can be concluded that autumn ploughing provides the highest yield, but its effect significantly differed in irrigated and non-irrigated treatments. The periodical application of strip tillage is justified in areas with favourable soil conditions and free from compated layers (e.g. strip – strip – ploughing – loosening). Under conditions prone to drought, but especially in several consecutive years, a plant density of 70–80 thousand crops per hectare should be used in the case of favourable precipitation supply, but 60 thousand crops per hectare should not be exceeded in dry crop years. The yield increasing effect of fertilisation is significant both under non-irrigated and irrigated conditions, but it is much more moderate in the non-irrigated treatment.
Selecting the optimum sowing date is of key importance from the aspect of maize yield, especially in dry crop years. Irrigation is not enough in itself without intensive nutrient management, since it may lead to yield decrease.
The results of research, development and innovation, which are based on the performed long-term field experiment, contribute to the production technological methods which provide an opportunity to use sowing seeds, fertilisers and pesticides in a regionally tailored and differentiated way, adapted to the specific needs of the given plot, as well as to plan each operation and to implement precision maize production.
...5); font-variant-ligatures: normal; font-variant-caps: normal; -webkit-text-stroke-width: 0px; text-decoration-style: initial; text-decoration-color: initial;">The aim of this study was to analyse the problems caused by the unfavourable (dry and wet) weather and its consequences in the R1 growth stage of maize (Zeamays L.), as well as their management and the alternatives of preventing yield reduction by using agrotechnical measures fertilisation, irrigation), also, we wanted to examine whether the Chl content measured in the R1 growth phase provides reliable prediction of yield per hectare.
We evaluated the relationships among soil cultivation and other agrotechnical factors (fertilization, number of plants and hybrid) within the framework of a multifactorial long-term experiment set at the Látókép Experimental Site of the Centre for Agricultural Sciences of the University of Debrecen in mid-heavy chalcareous chernozem soil bas...ed on a long-term experiment conducted for a 5-year period (2002–2006).
Based on the evaluation of soil cultivation by the average of treatments, it may be assessed that spring ploughing (8.204 t ha-1) provides more favourable conditions to the stand compared to spring shallow cultivation; however, this did not result in a significant difference. Spring ploughing considerably increased the yield of hybrid FAO 300 in dry years, whereas it considerably increased the yield of hybrid FAO 400 in favourable crop years. A stand of 70 thousand stems/ha provided the higher yield result in both soil cultivation types. It was sufficient to use a fertilizer dose of 120 kg N ha-1 for economical production.
We carried out the tests in the flood meadow soil formed on the alluvial cone of Nagykereki, Sebes-Körös belonging to the Bihar plane small region. The aim of the study was to analyse the effect of the different sowing date of maize on the yield trend based on a comprehensive study conducted for 6 years (2007–2012).
The sowing date...of maize hybrids is a factor that significantly influences yield, however, its effect is not significant in each crop year. In the years when the date of sowing has a modifying effect, the reliable yield level can be reached with optimal sowing date management (24 April).
The advantage of early sowing (10 April) proved to be dominant in the year of 2012, the seeds were placed into the still wet soil therefore shooting was more balanced. Maize seeds sown at the time of optimal (24 April) and late (10 May) sowing dates were placed into the already dry soil, which deteriorated germination and the strength of early initial development that had an effect on the yield.
The effect of crop production factors on maize yield are examined on chernozem soil in a more than 30 year old long-term experiment on the Látókép Experiment Site of the Centre for Agricultural and Applied Economic Sciences of the University of Debrecen. The aim of research is to evaluate the effect of fertilisation, cultivation, plant numbe...r, genorype and irrigation. The analysis of the data in the database of the examined period makes it possible to evaluate the effect of maize yield, as well as that of the crop production factors and the crop year, while the correlations and interactions between these factors were also examined. During the examination of the cultivation treatments, it was concluded that the highest yield was obtained as a result of autumn ploughing, but its effect largely differs in the irrigated and the nonirrigated treatments. Based on our examinations, strip cultivation should be applied periodically (e.g. strip – strip – ploughing – loosening) in areas with favourable soil conditions free from compacted layers.
In years with smaller, average precipitation supply or when the precipitation was higher than average, higher plant numbers were more favourable. Under drier conditions, but especially in several consecutively dry years, a lower plant number can be recommended which is not higher than 60 thousand per hectare. In the case of favourable water supply, 70-80 thousand plants per hectare can be used. The yield increasing effect of fertilisation was significant in the case of both non-irrigated and irrigated conditions, but it was much more moderate in the non-irrigated treatment. The extent of weed coverage was significantly affected by the previous crop. In the case of a favourable previous crop (wheat), the weed coverage was significantly lower than after an unfavourable previous crop (maize). In the case of the same previous crop (maize), the extent of weed coverage was mostly determined by the crop year and the extent of precipitation supply. Irrigation is not enough in itself, because if it was not accompanied by intensive nutrient management, yields started to decline.
The results of researhc, development and innovation contributed to the technological method which makes it possible to apply locally adjusted sowing seed, fertiliser and pesticide in a differentiated way, as well as to change the method of operations within the given plot.
The effect of N doses on the yield and nutritional values of the Sushi (FAO 340) maize hybrid were analysed in three years (2018, 2019, and 2020). The analyses were performed at the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil, in a striped, small-plot, non-irrigated...long-term field experiment. In the experiment, in addition to the non-fertilized treatment (A0), the N-fertilizer doses were applied as basic fertilizer and top dressing. The 60 and 120 kg N ha-1 dose (A60, A120) applied as spring basic fertilizer were followed by two phases of top-dressing in V6 (V690, V6120) and V12 (V12150, V12180) phenophases; the amounts were +30 and +30 kg N ha-1.
Maize yields were affected to varying degrees by crop year. The highest yields in 2018 and 2020 were recorded in the same V6150 treatment, while in 2019 the highest yield was obtained in the A120 treatment.
Increasing the N doses resulted in an increase in the protein content of the maize kernel. Depending on the fertilizer treatments and the crop year effect, the protein content of maize kernels varied between 6.2–10.2 g x 100 g-1. In all three years, the protein content was the lowest in the control treatment (A0) and the highest in the V6150 treatment.
The starch content ranged from 70.7 to 77.9 g x 100 g-1 in the average of the three years. In 2020, it was significantly higher in all nutrient treatments than in the other examined two years. The highest starch content - except for 2020 (A120, 77.9 g x 100 g-1) - was recorded in the A0 treatment (74.2, 72.3 g x 100 g-1).
The oil content of maize kernels varied between the values of 3.8 and 5.2 g x 100 g-1 in the average of three years. In terms of oil content, the results for 2018 and 2019 can be considered the same, while in 2020 it was significantly lower. Fertilizer treatments did not significantly affect the oil content of maize in any of the years.
The fertilizer dose applied in the V12 phenological phase was not effective in terms of yield and nutritional content (protein, starch and oil content).
In the growing season of 2019, we analysed stress resulting from climatic factors on maize hybrids of different genotypes, with the aim of gaining a better understanding of the physiological responses of each hybrid, which might support the elaboration of a cost-effective irrigation plan.
Our experiments were carried out at... the Látókép Experimental Station of the University of Debrecen on calcareous chernozem soil in a small-plot long-term field trial with strip plot design. In the scope of the experiment, N-fertilizer doses were applied as basic fertilizer and top-dressing in addition to the non-fertilized (control) treatment. The 60 and 120 kg N/ha doses applied as basic fertilizers in the spring were followed by top-dressing in the V6 phenophase with a +30 kg N/ha dose. Measurements were carried out with the involvement of the Renfor early (FAO 320) and Fornad (FAO 420) late maturity hybrids-
The stomata of the plants became more and more closed with the progression of the phenological phases; their stomatal conductance decreased. However, the hybrids responded differently to environmental stress. In the case of the Renfor hybrid, the highest conductance (669 mmol/m2-s) was recorded in the V12 phenophase with the 150 kg N/ha treatment. The stomata were more open due to the high turgor pressure, allowing plants to evaporate properly. The plant was in its worst physiological condition on 2nd July, at the time of the appearance of the last leaf in the case of the 120 kg N dose (224 mmol/m2-s). The value measured in the V12 phenophase has already shown that the stomata were closing due to the self-regulating system of the plant. It would have been necessary to dispense irrigation water following the measurement. This confirms the finding that water stress can be prevented by measuring stomatal conductance.
In the case of the Fornad hybrid, stomatal conductance was the highest on 12th June (630 mmol/m2-s) in the 90 kg N/ha treatment and it was the lowest (183 mmol/m2-s) in VT (emergence of the last leaf) phenophase in the 60 kg N/ha treatment. In this case, the appropriate time for applying irrigation water would have been early July, when the conditions for the plants were still adequate. Subsequently, the stomata began to close due to a reduction of the water resources available to them.
There was a significant correlation between soil moisture and stomatal conductance, as well as between temperature and stomatal conductance.
The impact of the climatic factors of crop year on the relative chlorophyll content of maize was examined for three years. The examinations were carried out on the Látókép Experiment Site of the University of Debrecen on calcareous chernozem soil in a small-plot, non-irrigated long-term field experiment with strip plot design. In addition to... a non-fertilised (control) treatment, nitrogen (N) fertiliser doses were applied as base and top dressing. The 60 and 120 kg N ha-1 base dressing doses were followed by two top dressing doses at the V6 and V12 phenophases.
Averaged over the different fertiliser treatments, SPAD readings increased in all three years as the growing season progressed. The highes SPAD value increase was observed in the average crop year (2017) at the V12 phenophase (11.8), which further increased at the R1 phenophas, by 3,7. No significant Spad value difference was observed between the average (2017) and the dry year (2018) at the V6 growth phase. However, in the wet crop year (2016), the V690 treatment provided the statistically highest relative chlorophyll content (46.8). At the V12 phenophase, the base dressing dose of 120 kg N ha-1+30 kg N ha-1 (V6150) showed to be successful in two years (2016 and 2018), while in 2017, the base dressing dose of A60 was successful. The impact of crop year on relative chlorophyll content can be clearly shown at the R1 growth stage. In all three years, the significantly highest relative chlorophyll content could be achieved at different nutrient levels: A60 in 2016, V6150 in 2017 and V690.
In a wet year (2016), higher yield could be achieved as a result of the 60 kg N ha-1 base dressing and 30 kg N ha-1 at the V6 growth stage (V690) as top dressing in comparison with 2017 and 2018, when higher fertiliser dose (120 kg N ha-1 base dressing and 30 kg N ha-1top dressing at the V6 growth stage) was needed to achieve a significant yield surplus.
Altogether, averaged over the different treatments, the highest yield (12.48 t ha-1) was observed in the wet year, when the relative chlorophyll content was also the highest (50.6).