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Evaluation of the Effect of Conventional and Stabilized Nitrogen Fertilizers on the Nutritional Status of Several Maize Cultivars (Zea mays L.) in Critical Growth Stages Using Plant Analysis
The study presents the results of a three year field trial aimed at assessing the nutritional status of maize in critical growth stages by means of a plant analysis in the cultivation of three maize cultivars differing in their agronomic and genetic profile. The main research problem was to demonstrate whether the availability of nitrogen from stabilized fertilizers for “stay-green” maize varieties is consistent with the dynamics of the demand for this component. This is very important from both the economic and agronomic aspect of maize cultivation. The research showed a significant response of the maize cultivars to different nitrogen fertilizer formulations, which was observed in the period from the five-leaf stage to the full flowering stage. The advantage of the fertilizer, UltraGran stabilo, over other nitrogen fertilizers in the BBCH 15 stage was demonstrated only for the cultivar, ES Metronom, which produced a greater aerial mass while maintaining the nitrogen concentration at the level of the other two maize cultivars. The nitrogen and potassium content shaped the kernel weight in the ear in the flowering stage, confirming the importance of the interaction of these two elements in forming this feature of maize as the main predictor of the grain yield. This trait (expressed by the R2 coefficient) manifested each year of the study, but especially in the years with optimal weather patterns (i.e., the first year). The response of the maize cultivars to nitrogen fertilizers, especially the cultivar, ES Metronom, was manifested by an increase in the content of nutrients and chlorophyll in the ear leaf, that is considered a predictive organ for grain yield. The fertilizers, Super N-46 and UltraGran stabilo, had a positive effect on the chlorophyll content (CCI parameter) and increased its efficiency of excitation energy transfer (the F0 parameter).
Evaluation of the Effectiveness of NBPT and NPPT Application as a Urease Carrier in Fertilization of Maize (Zea mays L.) for Ensiling
The study presents the results of a 3-year field trial aimed at assessing the yield and quality of raw material for ensiling in the cultivation of three maize varieties differing in their agronomic and genetic profile, conditioned by the selection of nitrogen fertilizer. Maize cultivar ES Metronom showed a significant advantage over other cultivars when fertilized with UltraGrain stabile, or alternatively Super N-46. The application of nitrogen-stabilized fertilizers or urea + N-Lock significantly increased the yield of maize green fodder for ensiling. The “stay-green” maize cultivars were characterized by a higher content of non-structural carbohydrates, including starch and water-soluble sugars, and a lower content of structural carbohydrates, compared to the conventional cultivar, which increased their suitability for ensiling. The negative effect of maize fertilization with ammonium nitrate and ammonium nitrate + N-Lock on the chemical composition of green fodder was demonstrated by a reduced starch content and increased structural carbohydrate contents, including crude fiber and NDF. In turn, the positive effect of maize fertilization with urea and urea + N-Lock on the chemical composition of maize fodder was shown by increased starch content and reduced structural carbohydrate contents, including crude fiber and its NDF and ADF fractions. The analysis of the number and weight of leaves may indicate a highly effective utilization of nitrogen (“stay-green” maize hybrids), leading to the faster formation of leaves with a larger assimilation surface, which is the basis for the efficient absorption of solar radiation. The results obtained clearly show that only the correct choice of maize variety for silage cultivation, combined with nitrogen fertilizer guaranteeing access to N during the growing season, can guarantee a high yield for ensiling.
Deficiencies of Secondary Nutrients in Crop Plants-A Real Challenge to Improve Nitrogen Management
Secondary nutrient (e.g., calcium, magnesium, sulfur) deficiencies in crop plants disturb the nitrogen balance in the plants, thus reducing the overall yield. This hypothesis was analyzed based on the physiological functions of these nutrients, in relation to the uptake and utilization of N, in crop plants. Nitrogen uptake by plants requires a well-developed root system, the size of which depends on the supply of calcium. This process is largely controlled by the content of toxic aluminum in the soil, which can be mitigated through the application of lime and/or gypsum. In humid climates, the excessive uptake of calcium by plants occurs during water shortages; this process significantly interferes with N uptake. Magnesium, which affects plant growth throughout the growing season, can effectively control excessive calcium uptake. Magnesium deficiency can be ameliorated with soil- or foliar-applied fertilizers. These stages define the timing of plant sampling and determination of the N:S ratio, as an indicator of plant nutritional status. The application of Mg, S, or MgS facilitates higher productivity of fertilizer N by narrowing the N:Mg and N:S ratios in plants. The use of secondary nutrients can allow farmers to obtain high yields while reducing both production costs and environmental risks.
Improving Forage Quality from Permanent Grasslands to Enhance Ruminant Productivity
Permanent grasslands play a crucial role in ruminant nutrition, providing cost-effective and nutritionally rich forage. Their effective management is essential for improving agricultural productivity and sustainability. This review examines factors affecting forage quality, including environmental conditions, botanical composition, conservation methods, and fertilization strategies. The impact of grassland management practices, such as cutting frequency, grazing systems, and soil fertility enhancement, on forage nutritional value is discussed. Advances in breeding, including genomic selection and molecular techniques, offer opportunities to improve digestibility and resistance to environmental stress. Furthermore, conservation methods, including haymaking and silage production, significantly influence forage quality. Special attention is given to the role of legumes and multi-species swards in enhancing protein content and mineral composition. The review highlights that optimizing forage quality requires an integrated approach, combining agronomic practices, genetic improvements, and sustainable management strategies. Future research should focus on developing resilient forage systems that maintain high nutritional value while adapting to changing climatic conditions.
Challenges of Pasture Feeding Systems-Opportunities and Constraints
Grazing plays an important role in milk production in most regions of the world. Despite the importance of grazing, current trends in livestock farming in Europe are causing a decline in the popularity of pasture-based feeding of dairy cows. This paper aims to provide an overview of the challenges faced by the pasture feeding system under climate change. Grazing lands provide ecosystem services including regulation and storage of water flows, nutrient cycling, and C sequestration. Livestock grazing is the most important factor shaping and stabilizing pasture biodiversity. Some opportunities for pasture feeding are the health-promoting and nutritional qualities of milk and milk products, especially milk from pasture-fed cows. The beneficial effects of pasture feeding on animal health and welfare are not insignificant. Available organizational innovations can help better manage livestock grazing and, above all, better understand the impact of the grazing process on the environment and climate change.
Productivity of Nitrogen Accumulated in Alfalfa–Grass Sward Cultivated on Soil Depleted in Basic Nutrients: A Case Study
The productivity of fodder legumes, based on internal sources of N, may be limited due to an insufficient supply of nutrients responsible for the efficient use of N accumulated by the crop during the growing season. Production risk occurs on soils that are naturally poor or depleted in nutrients that are decisive for the fixation and utilization of N2 by alfalfa. This hypothesis was validated on the basis of a field experiment with an alfalfa–grass mixture carried out over three main seasons (2012−2014) on soil low in available potassium (K), calcium (Ca), and sulfur (S). The experiment involved two factors that contained two levels of applied gypsum (GYP: 0, 500 kg ha−1) fertilized with P and K (POT: absolute control—AC, P60K0, P60K30, P60K60, and P60K120). In each main season of the alfalfa–grass mixture, the sward was mowed three times (three cuts). The total sward yield (TY) reached its maximum in the second main season (15.6 t DW ha−1), then it significantly decreased. The sward yield of the third cut was the main driver of the TY. The content of P in the first cut, and especially P and S in the third cut of the sward, affected the N:P and P:S ratios, which, in turn, determined the productivity of the alfalfa–grass mixture. The total amount of accumulated N (TN) in the sward significantly responded to gypsum and PK fertilizers. In the first and third main seasons, the highest TN was found on the plot fertilized with both gypsum and 120 kg K2O ha−1. In the second main season, the TY was determined by PK dose, being variable in successive years. The highest total N accumulation (TN) was recorded in the second main season. It reached 504 kg N ha−1 on the plots with GYP−0 and 436 kg N ha−1 for GYP−500. However, the corresponding TY was 16.7 and 17.3 t DW ha−1. This apparent discrepancy was due to the much higher productivity of N, which was 33.2 and 39.6 kg fodder DW ha−1 TN, respectively. These two characteristics clearly indicate that the productivity of the accumulated N by the alfalfa–grass sward was significantly restricted by the shortage of P and S. The studies clearly emphasized that the sward of the alfalfa–grass mixture grown on soil depleted in available K, Ca, and S responds significantly to the combined application of gypsum and potassium, but provides effective control of the P supply, even on soil rich in available P.