Application of photometry for diagnostics of nitrogen nutrition in spring barley

The article discusses a method for diagnosing nitrogen nutrition of spring barley (Hordeum vulgare L.) in different phases of the growing season using a photometric device (N-tester) Yara. The studies were carried out in the conditions of the Moscow region (Russia) on the Mikhailovsky spring barley variety on sod-podzolic medium loamy soils with a high and medium content of phosphorus and potassium and a low content of humus (1.9). The agrometeorological conditions of the growing season of spring barley were characterized by sharp fluctuations in air temperature and the amount of precipitation over decades of the month and in comparison with average long-term observations. Abundant and prolonged precipitation during the grain ripening phase led to lodging in most of the experiments, which affected the yield. To diagnose crops, a model experiment was laid with the introduction of increasing doses of nitrogen fertilizers into pre-sowing cultivation with a step of 30, at which the dose of nitrogen ranged from 30 to 150 kg/ha. Diagnostics was carried out in three phases of vegetation: tube emergence ((Z42), earing (Z55), milk ripeness of grain (Z73) with the Yara N-tester and with the help of stem diagnostics according to the modified method of V. Zerling. The results of photometric diagnostics in the stemming phase (Z42) have a strong correlation with the yield of spring barley grain and with the results of stem diagnostics (R = 0.85). Wherein, the N-tester readings in the earing phase (Z55) and milk ripeness of grain (Z73) with yield R = 0.23 and R = 0.17, respectively, have a weak correlation. This is possibly due to lodging of crops and a change in yield, not as a result of poor plant nutrition, but with difficult mechanized harvesting.

Nitrogen use by plants and nitrogen flows after application of standard and biomodified nitrogen fertilizers on barley

The aim of our study was to assess the efficiency of application of biomodified nitrogen fertilizers for barley, to reveal the sources of nitrogen used for biomass formation with the use of the 15N stable isotope, and to study nitrogen flows in the system of fertilizers–soil–plants–atmosphere. We demonstrated in a model experiment the ability of the plant growth-promoting bacteria Bacillus subtilis Ch-13 to move from the granules of mineral fertilizers to plant roots and to colonize them effectively. The effectiveness of biomodified nitrogen fertilizers for barley, Nur variety, was assessed in a microfield trial. After the application of biomodified nitrogen fertilizers, the accumulation of 15N in the plants increased by 2–5 %, its incorporation in the soil decreased and gaseous losses were decreased by 7 % as compared with the use of the usual forms of fertilizers. The application of biomodified nitrogen fertilizers can be used in agricultural practice as a novel technology to regulate nitrogen flows in the system of fertilizers–soil–plants–atmosphere.

Effects of Varying Rates of Nitrogen and Biochar pH on NH3 Emissions and Agronomic Performance of Chinese Cabbage (Brassica rapa ssp. pekinensis)

NH3 emitted into the atmosphere undergoes intricate chemical reactions to form fine particulate matter PM2.5. Nitrogen fertilizers are one of the major sources of gaseous ammonia. Recently, research into using biochar to lessen NH3 emissions from agricultural land has taken center stage and several studies have been executed in that regard. However, biochar’s capacity to reduce emissions of gaseous NH3 from applied nitrogen fertilizers is affected by both soil and biochar properties. While the effects of soil properties on NH3 volatilizations have been widely studied, the data concerning the effects of biochar properties on NH3 volatilizations from the soil are still scanty. It is against this backdrop that this study examined the effects of biochar pH on emissions of NH3 from the soil amended with varying quantities of nitrogen, as well as the impact on the growth and productivity of Chinese cabbage. To achieve the study objectives, acidic (pH 5.7), neutral (pH 6.7) and alkaline (pH 11.0) biochars were used and each was added to the soil at a rate of 1% (w/w). Nitrogen fertilizers were applied at three rates of 160, 320, 640 kg ha−1. In comparison with the control, the acidic, neutral and alkaline biochar amendments reduced NH3 emissions by up to 18%, 20% and 15%, respectively. However, only neutral biochar produced higher Chinese cabbage yields than the urea-only amendment and the Chinese cabbage yields increased with the increasing rates of nitrogen applied. Combined applications of neutral biochar and 640 kg/ha of nitrogen are recommended for optimal cabbage yields and low NH3 emissions.

Effect of biochar blended organic fertilizers on soil fertility, radish productivity and farm income in Nepal

Declining soil fertility and nutrient availability are one of the major threats to reducing crop productivity in Nepal. A field experiment was conducted to assess the potential of biochar (10 t ha-1) blended with organic and inorganic fertilizers on improving soil fertility and radish productivity in Morang district, Nepal. Biochar was prepared from locally available twigs, branches, and wood using the soil pit “Kon tiki” method. The experiment was laid out in Randomized Complete Block Design with 7 treatments having four replications viz., control (CK), biochar (BC), biochar + cattle manure (CM), biochar + poultry manure (PM), biochar + cattle urine (CU), biochar + commercial biofertilizers (BF) and biochar + inorganic fertilizers (urea-N). The nitrogen rate used in all the treatments was equivalent to 100 kg ha-1. The agronomic effect of biochar blended organic amendments was compared with control and inorganic urea-N treatments. Biochar amended plots showed significantly higher soil pH (6.5), organic matter (4%), total N% (0.8%), available P (80.1 kg ha-1), and K (203.6 kg ha-1) compared with control. CM increased marketable yield by 320% (63 t ha-1) and biomass yield by 198% (100 t ha-1) compared with control (15.0 t ha-1 and 34 t ha-1) of marketable and biomass yield, respectively. CM increased marketable yield by 44% compared with the urea-N treatment (44 t ha-1). Moreover, net return was observed highest with CM treatment among all the organic and urea-N treatments. The study suggests that the combination of biochar with locally produced cattle manure has the potential to increase radish productivity and could compete with mineral nitrogen fertilizers while producing similar or even higher crop yields and economic returns.

AGROENERGY EFFICIENCY OF IMPROVED TECHNOLOGIES FOR CREATION AND USE OF ALFALFA-CEREAL HAYMAKING IN THE NON-CHERNOZEM ZONE

On the basis of field experience in the creation of alfalfa-grass stands on sod-podzolic soil of the Non-Chernozem zone, a high agroenergetic efficiency of improved technologies has been established, including two zoned varieties of alfalfa changeable (Lugovaya 67 and Pastbishchnaya 88) in combination with agrotechnical methods (change in the composition of leguminous species in the previous period and pre-sowing inoculation of alfalfa seeds with complementary strains of Sinorhizobium meliloti). As a result of the application of the agro-energy method for assessing the production of exchangeable energy and total anthropogenic costs in uniform indicators according to the international SI system (GJ/ha), their payback was established — 8–11 times. This was achieved due to a high share of natural factors (88–91% of total costs), additional nitrogen input into the production process due to increased symbiotic fixation (141–171 kg/ha per year) and long-term use — for 7 years. The productivity of 1 hectare was 62–64 GJ/ha metabolic energy, the collection of protein was 956–1120 kg/ha, the saving of anthropogenic costs due to the exclusion of the use of nitrogen fertilizers was 17–21 GJ/ha.

The Effects of Foliar Vermicompost Applications on Yield and Some Yield Components in Triticale Varieties

Vermicompost fertilizers have started to attract attention in agriculture last years. Various liquid vermicompost fertilizers are produced and used in agriculture and some of them known as vermiliquer, vermi leachate, vermi tea or vermicast with little differences. This study is aimed to determine the effects of foliar application of liquid vermicompost fertilizer on yield and some yield components on some Turkey triticale varieties under Central Anatolian conditions in Kırıkkale province during the growing period 2014-15 and 2015-16. Six different (control, 75, 150, 250, 350 and 450 cc da-1) liquid vermicompost fertilizer doses were applied by the foliar spraying method at the beginning and end of March in both years to the five Turkey triticale varieties (Alperbey, Mikham 2002, Tatlıcak 97, Karma 2000 and Ümranhanım). According to the results, plant height, grain number and grain yield in spike, grain yield per decare, harvest index and protein content results were found to be significant in fertilizer × variety × year interaction. There is also a statistically significant difference between thousand-grain weight and the variety x fertilizer doses interaction, and between varieties and fertilizer doses in terms of spike length. The positive effects of liquid vermicompost fertilizer doses, except 450 cc da-1, were determined in varieties. It was observed that a satisfactory yield can be obtained from 250 cc da-1 in the absence of nitrogen fertilizers as the top fertilizer. It could be deduced that 250-350 cc da-1 doses of vermicompost fertilizer can be applied in triticale based on varying ecological conditions and varieties in Central Anatolian ecological conditions.

Rapid Detection of Urea Fertilizer Effects on VOC Emissions from Cucumber Fruits Using a MOS E-Nose Sensor Array

The widespread use of nitrogen chemical fertilizers in modern agricultural practices has raised concerns over hazardous accumulations of nitrogen-based compounds in crop foods and in agricultural soils due to nitrogen overfertilization. Many vegetables accumulate and retain large amounts of nitrites and nitrates due to repeated nitrogen applications or excess use of nitrogen fertilizers. Consequently, the consumption of high-nitrate crop foods may cause health risks to humans. The effects of varying urea–nitrogen fertilizer application rates on VOC emissions from cucumber fruits were investigated using an experimental MOS electronic-nose (e-nose) device based on differences in sensor-array responses to volatile emissions from fruits, recorded following different urea fertilizer treatments. Urea fertilizer was applied to cucumber plants at treatment rates equivalent to 0, 100, 200, 300, and 400 kg/ha. Cucumber fruits were then harvested twice, 4 and 5 months after seed planting, and evaluated for VOC emissions using an e-nose technology to assess differences in smellprint signatures associated with different urea application rates. The electrical signals from the e-nose sensor array data outputs were subjected to four aroma classification methods, including: linear and quadratic discriminant analysis (LDA-QDA), support vector machines (SVM), and artificial neural networks (ANN). The results suggest that combining the MOS e-nose technology with QDA is a promising method for rapidly monitoring urea fertilizer application rates applied to cucumber plants based on changes in VOC emissions from cucumber fruits. This new monitoring tool could be useful in adjusting future urea fertilizer application rates to help prevent nitrogen overfertilization.

Influence of Nitrogen Nutrition on Fatty Acids in Oilseed Rape (Brassica napus L.)

The aim of the study was to evaluate the effect of nitrogen nutrition on the content of fatty acids and selected qualitative parameters (nitrogenous substances, ash, crude fiber) in winter oilseed rape (Brassica napus L.). The experiment was carried out at the Vígľaš—Pstruša Research and Breeding Station in 2008–2009 and 2009–2010 by complete block design with four repetitions. Nitrogen fertilization was applied at four levels, plus an untreated control (after agrochemical soil analysis) by DAN 27 (Dolomite Ammonium Nitrate): 100, 120, 140, and 160 kg/ha N. Application date was in BBCH scale phase 59–60. The fatty acid contents (MUFA—monosaturated fatty acids; PUFA—polyunsaturated fatty acids) were determined by gas chromatography in the extracted fat, which is determined by extraction method. Within the result evaluation, statistically significant increases in the contents of linoleic and linolenic acids were recorded in all variants treated by nitrogen fertilizer, which is positive in terms of the use of rapeseed oil for food and energy purposes. The statistically significant decrease of oleic acid after the application of nitrogen fertilizers is negative for industry use of rapeseed oil.

Agroeconomic prospects for the use of nitrogen fertilizers for field crops

The issues of recoupment of nitrogen fertilizers are considered, since they determine the need for fertilizers and the agro-economic efficiency of their use. It is shown that the payback of fertilizers is a complex value and not constant in different crops. The increase in yield from fertilizers in kind is taken on the basis of field experiments with fertilizers carried out on podzolized chernozem of the opita field of the Uman NUS. The cost of an increase in the yield from the use of nitrogen fertilizers was determined by the average actual sales prices of products prevailing on the market through various sales channels in the 6th quarter of 2021. Additional costs included: the cost of fertilizers, a margin for their delivery to the farm, the cost of using it on the farm and collecting increase in yield from nitrogen fertilizers. The cost of ammonium nitrate was taken at UAH 24,000 / t with the addition of a margin for their delivery to the farm. The costs of using fertilizers on the farm and collecting an increase in yield were set calculated according to the accepted standards. The difference between the value of the yield increase (PU) and additional costs (AD) gives the net income received from the use of fertilizers. The ratio of the cost of increasing the yield to additional costs shows their payback. On the basis of comparing the indicators of PU and DZ, the boundaries of the economic efficiency of the use of fertilizers were determined: PU> DZ (general expression of the task). We also calculated the minimum required increase in yield from fertilizers and the limits of price increases for nitrogen fertilizers. It has been established that at a price of ammonium nitrate of UAH 24,000 / t and the cost of its use in optimal doses for field crops against the background of a balanced phosphorus-potassium nutrition, the cost of an increase in yield is 3075–47894 UAH/ha. Payback of 1 kg a.c. nitrogen fertilization varies in a wide range – from 3.0 to 217.3 hryvnyas, depending on the crop. The limit of the unprofitable price per unit of the active substance of nitrogen fertilizers at the optimal application rate depends on the crop and is in the range of UAH 76.5–219.0 /ha. With the current disparity in prices for crop products and ammonium nitrate (24,000 UAH/t), its use is profitable, which is explained by the low ability of podzolized chernozem to provide plants with nitrogen, biological requirements of crops for this food element and technologies for their cultivation. Key words: nitrogen fertilizers, agricultural crops, fertilizer recoupment, loss threshold, price increase limit.