Effect Of Nitrogen Fertilization Research Articles

Biochar Blended with Nitrogen Fertilizer Promotes Maize Yield by Altering Soil Enzyme Activities and Organic Carbon Content in Black Soil

Biochar and nitrogen fertilizers are known to increase soil carbon storage and reduce soil nitrogen loss as amendments, suggesting a promising strategy for highly effectively increasing soil productivity. However, few studies have explored the mechanisms of their effects on crop yield in terms of active carbon fraction and enzyme activity, which ultimately limits the potential for the application of biochar in combination with nitrogen fertilizers. To evaluate the effect of biochar and nitrogen fertilizer on the improvement of black soils in northeast China, a field experiment was conducted in the black soil to compare and analyze the application methods on total organic carbon (TOC), total nitrogen (TN), enzyme activities, and maize yields. Biochar rates: CK, C1, C2, and C3 (0, 9.8, 19.6, and 29.4 Mg·ha-1); N fertilizer rates: N1/2 and N (30 and 60 kg·ha-1). Results indicated that biochar and N fertilizer amendments significantly ameliorated soil fertility, such as TOC and TN, compared to the unamended soil. The TOC levels in the C3 treatment increased by 35.18% and the TN levels by 23.95%. The improvement in TN is more significant when biochar is blended with N fertilizer. Biochar blended with N fertilizer increased maize cellulase, urease, and invertase activities by an average of 53.12%, 58.13%, and 16.54%, respectively. Redundancy analysis showed that TOC, TN, and MBN contributed 42%, 16.2%, and 22.2%, respectively, to the maize yield indicator. Principal component analysis showed that reduced N fertilizer was more effective in improving yields, with a maximum yield increase of 50.74%. Biochar blended with N fertilizer is an effective strategy to improve the fertility and productivity of black soils in northeast China, while nitrogen fertilizer reduction is feasible and necessary for maintaining grain yield.

Effects of Different Irrigation Regimes and Nitrogen Fertilization on the Physicochemical and Bioactive Characteristics of onion (Allium cepa L.)

The availability of water and nitrogen in the soil affect the metabolism of onion bulbs. The synthesis of metabolites and bioactive compounds are the most affected, along with the quality of the onion bulbs However, it is necessary to know the effects of different water levels and nitrogen fertilization to optimize the quality of the onion. The objective of this research was to study the effects of the different conditions of hydric stress and nitrogen fertilization during the development of onion (Allium cepa L.) crop, regarding its physicochemical and bioactive properties. Onions were grown using four available irrigation regimes (25, 50, 75 and 100%) and four doses of nitrogen fertilization (100, 150, 200 and 250 kg N ha−1). Onion without any treatment was considered as a control. The treatments low in irrigation and nitrogen fertilization increased the pH level (5.7 to 5.9) and bulb coloration in bright white/yellowish tones. An increase was observed compared to control in titratable acidity (0.13%) just in the nitrogen content, ascorbic acid (46%) and antioxidant capacity with DPPH (12.3%) and ABTS (93.7%). A decrease was shown in soluble solids (14.6%), firmness (3.5 kg cm−2), dry matter (6.6%), total phenols (50%) and FRAP (33.2%) values. Pyruvic acid remained constant (1.5 µmol g−1 FW). The onion bulb extracts showed an erythroprotective effect with a hemolysis inhibition percentage higher than 95%. Finally, the onions had low pungency, and were soft and extra sweet. The treatments with 25% usable humidity and nitrogen fertilization of 150 and 250 kg ha−1, favored the physical, chemical and bioactive quality of the onion bulb.

Effect of biochar and nitrogen fertilizers on maize seedling growth and enzyme activity relating to nitrification

AbstractMaximizing nitrogen use efficiency (NUE) involves synchronizing the interplay between nitrogen preferential crops and the nitrogen transformation pathways of soil. Biochar may benefit specific N‐preference crops in relatively unsuitable soil environments; however, experimental data are lacking. This study tested eight treatments, consisting of four nitrogen treatments (N0 = control; N1 = NH4Cl; N2 = NaNO3; and N3 = 1:1 ratio of NH4+ and NO3−) each with biochar applied at 0% or 2% (w/w). The results show that biochar and/or nitrogen application enhanced maize seedling biomass and NO3−‐based fertilizer resulted in higher seedling biomass than NH4+‐based fertilizer. With the application of biochar and NH4+‐based fertilizer, maize seedling biomass increased and soil NH4+‐N content was significantly reduced compared with NH4Cl sole application. Correlation analysis and redundancy analysis revealed that SOC content and inorganic nitrogen content were the main factors influencing maize growth and N absorption. Biochar with or without nitrogen fertilizer (except N1 treatment) significantly increased β‐1,4‐glucosidase (BG) activity. Co‐application treatments also resulted in higher vector length, an indicator of C limitation—the increment might add to the risk of microbial C limitation. The activity of ammonia monooxygenase (AMO), a key enzyme in nitrification, decreased with the co‐application of biochar and nitrogen, suggesting the alteration of nitrogen transformation.

Grazing intensity and nitrogen fertilization effects on biomass and morphology of black oat roots in an integrated crop–livestock system

AbstractGrazing stimulates root and forage mass of perennial pastures, but few studies have addressed the effects of grazing on annual pastures which are often grown in short periods within integrated crop–livestock systems (ICLS). In these pastures, N fertilization is a common practice to increase forage mass, but its effects on root morphology are unclear. In a field experiment, we evaluated how grazing intensities (ungrazed, moderate, and heavy grazing) and N fertilization rates (0, 75, and 150 kg N ha−1) affected morphological attributes of oat (Avena strigosa Schreb.) roots and forage accumulation in ICLS in Brazilian subtropics. Forage mass was evaluated in each grazing cycle and roots were sampled to a 30‐cm depth at the end of the grazing season in 2 years. Heavy and moderate grazing reduced (p < 0.05) forage accumulation by 15%–37% compared to ungrazed (4867 kg DM ha−1) in the first year, characterized by extended periods of water deficit, but in the second year forage accumulation from grazed and ungrazed was similar (p > 0.05), averaging 4273 kg ha−1. N fertilization increased forage accumulation in both the years, without differences between 75 and 150 kg N ha−1 in grazed treatments. Grazing and N rates mainly reduced root diameter and increased root N concentration. Increasing N fertilization rates increased root length but it was more expressive in the first year. Nitrogen fertilization with 75 or 150 kg N ha−1 on moderately grazed oat is an alternative to increase forage accumulation as it stimulates fine root development and increase N uptake, mainly when adverse climatic conditions can affect pasture growth.

Effect of Nitrogen Fertilization on Tree Growth and Nutrient Content in Soil and Cherry Leaves (Prunus cerasus L.)

Nitrogen fertilization ensures the proper growth of trees. The aim of the study was to evaluate the impact of differentiated nitrogen fertilization on selected parameters. It was assumed that such analysis is an indirect picture of the needs of cherries grown in herbicide fallow. The content of minerals in two layers of the soil, in leaves, and its influence on tree growth, and the content of chlorophyll in leaves were assessed. The experiments were carried out in three different cherry orchards. Three levels of fertilization were applied in each orchard: 0 kg, 60 kg, and 120 kg N ha−1. As expected the fertilization resulted in an increase in the content of nitrate and ammonium forms of nitrogen in the soil, however, their content was also dependent on precipitation and temperature. Additionally, high nitrogen fertilization increased the content of phosphorus and potassium and decreased the magnesium in the topsoil layer. High nitrogen fertilization caused the decreased content of phosphorus and potassium in the leaves. The level of calcium and magnesium in leaves increased with fertilization of 60 kg N ha−1 but decreased with the dose to 120 kg N ha−1. The use of nitrogen fertilization increased the vegetative growth of trees measured by leaf area and trunk cross-sectional area. However, the chlorophyll content was not dependent on the amount of nitrogen fertilization. Based on the results, it can be concluded that 60 kg N ha−1 is the optimal dose, ensuring proper nutrition of cherry trees.

Effects of nitrogen and phosphorus fertilization on soil organic matter priming and net carbon balance in alpine meadows

AbstractFertilizers‐induced priming effects of soil organic matter (SOM) decomposition influences net carbon balance and nutrient release. We hypothesize that very strong limitation of plant productivity and microbial activities by nitrogen (N) and phosphorus (P), common in Tibetan meadows, retard SOM decomposition and turnover. Consequently, N and/or P fertilization will induce priming effects of SOM and have implications for carbon balance. Soils from a nine‐year fertilization experiment (N alone, P alone, NP together, and control) from a Tibetan alpine meadow were used to investigate priming effect of SOM and carbon balance after addition of 13C labeled glucose. N and/or P fertilization acidified soil by 0.5 pH unit, decreased SOM content, and increased total and available N, total P. Regardless of fertilization, glucose addition accelerated SOM decomposition with priming effects of 30–60 μg C g−1 soil during 78 days. Alleviation of N and P limitation by N and NP fertilization lowered the priming effect by 17% and 14%, respectively, but P fertilization increased priming effect by 67%. The negative correlation of priming effect intensity with SOM, nitrate or total N, and microbial biomass contents indicated that fertilization‐induced differences in soil N and the microbial community are responsible for the priming effects. Positive correlation of carbon balance with total N and ammonium contents suggested that soil N accounts for carbon sequestration. Therefore, long‐term N and/or P fertilization accelerate SOM decomposition and reduce SOM storage in alpine meadows, of which P fertilization induces the highest priming effect and the lowest SOM storage.

Suitable nitrogen fertilizer application drives the endosperm development and starch synthesis to improve the physicochemical properties of common buckwheat grain

The effects of nitrogen (N) fertilizer on endosperm development, starch component, key enzyme activity and grain quality of common buckwheat were investigated in this study. The results showed that N fertilization significantly enhanced the number and area of endosperm cells, and significant increases were also observed in the contents of amylose, amylopectin and total starch. With increasing N level, the activities of key enzyme significantly increased showing the maximum under the N2 level (180 kg N ha−1), and then decreased under high N level. As N level increased, the ash, crude protein and amylose content varied from 1.36 to 2.25 %, from 7.99 to 15.84 % and from 22.69 to 27.64 %, respectively. The gelatinization enthalpy significantly increased with the range of 3.46–5.66 J/g, while no change was found in crystalline structure of common buckwheat flour. These results indicated that appropriate N application could effectively improve the endosperm development, starch synthesis and accumulation, and grain properties of common buckwheat, with the best effect under the level of 180 kg N ha−1.

Effects of Nitrogen Fertilization on Yield and Nitrogen Utilization of Film Side Planting Rapeseed (Brassica napus L.) Under Different Soil Fertility Conditions

Effects of Nitrogen Fertilization on Yield and Nitrogen Utilization of Film Side Planting Rapeseed (Brassica napus L.) Under Different Soil Fertility Conditions

Soybean yield response to nitrogen and sulfur fertilization in the United States: contribution of soil N and N fixation processes

ContextSoybean [Glycine max (L.) Merr.] is the most important legume grown worldwide. The effect of nitrogen (N) and sulfur (S) fertilization on seed yield is commonly studied in the United States (US). However, soybean yield response to fertilization remains inconsistent, partly due to the lack of standardized field designs and a better understanding of the plant nutrition processes underpinning yield formation. ObjectiveThe aims of this study were to assess the i) seed yield, (ii) plant N status (as N nutrition index, NNI), (iii) the contribution of N fixation, and (iv) the uncertainties on i), ii), and iii) in response to N-S fertilization using a uniform protocol across environments. MethodsTwenty-six trials in twelve US states tested five fertilization strategies that combined N and S at varying rates and timings. Using Bayesian statistics, seed yield response to fertilizer, NNI, and contribution of N fixation were analyzed at site and treatment levels providing both magnitude of responses and estimation of their uncertainties. From the significance of responses on seed yield, sites were split into two groups: non-responsive (18 sites) and responsive (8 sites). The NNI, ratio of the actual to the critical plant N concentration, was calculated to diagnose soybean N deficiency, and the N derived from the atmosphere (Ndfa, %) as N fixation contribution were investigated to better understand the source of plant N across all sites. ResultsRoughly for three-fourths of the sites, fertilization resulted in an unlikely (non-responsive) yield effect, with uncertainties ranging from 0.09 to 2.62 Mg ha−1. The other one-third of the sites were mainly responsive to S or both N + S, with the yield responses ranging from − 0.42–1.1 Mg ha−1 and uncertainties varying from 0.47 to 1.36 Mg ha−1. For the yield responsive sites, NNI presented a high proportion of deficiency (NNI<1) for most of the treatments, except for the “Full” signaling to a potential for yield response. Likewise, only 6% of the changes in Ndfa were not related to the treatment “Full”, and regardless of the seed yield response to fertilization, within the same site, soil and N fixation showed similar contributions to plant N demand. ConclusionDue to the high uncertainty in treatment response and contribution of N fixation, N fertilization is unlikely to increase yields, leading to non-profitable recommendations. Sulfur deficiency, on the other hand, should be explored under site-specific conditions. A decision support system should include appropriate diagnosis methods for identifying N and S deficiencies, such as NNI in soybean. Attainable maximum Ndfa did not appear to be affected by fertilization but largely varying depending on the site. ImplicationsFuture research should assess the role of soil and meteorological variables underpinning N fixation and soil N, along with the impact on seed quality composition, as a critical trait for this crop.

Effect of Nitrogen and Phosphate Fertilizer on Phosphorus Uptake and Phosphorus Use Efficiency in Some of Wheat Varieties (T. aestivum and T. durum)

A field experiment was carried out in a subtropical region of India. The main purpose of this experiment was to grow different wheat genotypes under different nutrient doses and find out which genotype performed better in terms of yields and other attributes under nutrient constraints. Nine varieties of wheat (T. aestivum and T. durum L.) were selected and grown as test crops in the current investigation, adopting a split plot design that was replicated three times, with nutrient dose as the main plot and varieties as sub treatments. In the treatmentT1 = control, T2 = 100% (N+P+K), T3 = 50% N+100% (P+K), and T4 = 50% P+100% N+K, there are 36 plots in a block (9 varieties x 4 fertilizer N and P treatments). Of the nine varieties grown under normal N and P conditions, varieties NARMADA 14 and GW 366 had the highest P content in grain and straw. GW366 (10.93 kg/ha) had the highest average total P uptake, followed by NARMADA14 (10.90 kg/ha). Under normal doses of N and P, the variety HI 1531 (15.25%) had the highest apparent recovery of P, followed by NARMADA14 (15.15percent).Across all fertilizer N and P dosages, the highest average agronomic efficiency for P was found in GW366 (40.09%), followed by LOK1 (37.93%). NARMADA 14 and GW366 have the highest P content in grain and straw of the nine varieties grown under normal nitrogen conditions. Agronomic use efficiency and physiological use efficiency were generally substantially higher when computed on a P basis than they were when calculated on an N basis. P fraction concentrations in black soil varied, but they responded similarly to crop species and N sources. The N supply had an impact on the amounts of P taken from the soil. In P-deficient soils, the use of an appropriate N source and the selection of the right crop species may boost crop yield and plant P uptake.

Effects of Water Stress, Nitrogen, Magnesium and their Interactions on Some Growth Characteristics and Essential Oil content of Rosemary (Rosmarinus officinalis L.)

A factorial experiment was applied with four replicates on rosemary plants (Rosmarinus officinalis L.) grown in pots inside the glasshouse of the Department of Biology, College of Science, Salahaddin University, Erbil, Iraq, during April, 2019 to July, 2020, to determine the effects of soil moisture content ( SM1: 100% and SM2: 60% field capacity), nitrogen fertilizer (N1: 100, N2: 200 and N3: 300kg/hectare), and magnesium fertilizer (Mg1: 0.0, Mg2: 30 and Mg3: 60kg/hectare) and their interactions on some growth characteristics and essential oil content of rosemary plants. Two cuttings were taken from rosemary shoots (on March, 2020 and July, 2020) after 12 and 15 months of planting respectively. Results showed that cutting 1: SM2 decreased plant height, number of branches, Shoot fresh weight (FW), shoot dry weight (DW), leaves DW &amp; stem DW. N3 increased plant height, number of branches, Shoot FW, shoot DW, leaves DW, stems FW &amp; stem DW. Interaction treatment SM1N3Mg3 increased plant height, Shoot FW, shoot DW, leaves DW, stems FW and stem DW, while in cutting 2: SM2 decreased shoot DW, stems FW and stem DW. N3 increased Shoot FW and stem DW. Mg3 increased Root FW, but decreased stems FW. SM1N3Mg1 increased stem DW. In cutting 1+ cutting 2, SM2 decreased accumulative stem DW and biological yield FW. N3 increased accumulative Shoot FW; Accumulative leaves DW, accumulative stem FW, accumulative yield FW and biological yield DW. Mg3 increased biological yield FW, while SM1N3Mg3 treatment increased accumulative shoot DW, accumulative leaves DW, biological yield FW, and biological yield DW. In the second harvest, SM2 and Mg2 decreased rosemary essential oil %, N3 and SM1N3Mg2increased EO% and concrete content, while SM1Mg2 increased EO.

Integrating microRNAs and mRNAs reveals the hormones synthesis and signal transduction of maize under different N rates

The effect of nitrogen (N) fertilizer on the development of maize kernels has yet to be fully explored. MicroRNA-mRNA analyses could help advance our understanding of how kernels respond to N. This study analyzed the morphological, physiological, and transcriptomic changes in maize kernels under different N rates (0, 100, 200, and 300 kg ha–1). The result showed that increasing N application significantly increased maize grains’ fresh and dry weight until N reached 200 kg ha–1. Higher levels of indole-3-acetic acid, cytokinin, gibberellin, and a lower level of ethylene were associated with increased N applications. We obtained 31 differentially expressed genes (DEGs) in hormone synthesis and transduction, and 9 DEGs were regulated by 14 differentially expressed microRNAs (DEMIs) in 26 pairs. The candidate DEGs and DEMIs provide valuable insight for manipulating grain filling under different N rates.

Combined Effect of Nitrogen Fertilizer and Plant Growth Promoting Rhizobacteria on Wheat (Triticum aestivum L.)

Combined Effect of Nitrogen Fertilizer and Plant Growth Promoting Rhizobacteria on Wheat (Triticum aestivum L.)

Oat–Field Pea Intercropping for Sustainable Oat Production: Effect on Yield, Nutritive Value and Environmental Impact

The aim of the study is to evaluate the effect of Oat–field pea intercropping on the yield, nutritive value, and environmental impact of oat grown under a reduced level of nitrogen fertilisation. The trial was laid out in a randomized complete block design with the following treatments: oat-0 (oat (Avena sativa L., SRCP X 80 Ab 2291 variety) without N fertilization (urea)), oat-23 (oat fertilised with 23 kg N/ha), oat-46 (oat fertilised with 46 kg N/ha), O1P1 (oat intercropped with field pea (Pisum sativum L., local variety) a ratio of 1:1), O1P2 (oat intercropped with field pea a ratio of 1:2), and O2P1 (oat intercropped with field pea at a ratio of 2:1). All of the experimental plots received standard husbandry practices except for nitrogen fertilisation. Soil pH, organic matter, total nitrogen, available phosphorus, and organic carbon were determined before and after planting. The effect of nitrogen fertilization and intercropping of oat with field pea on carbon footprint, acidification footprint, eutrophication footprint, and human toxicity footprint was calculated for each plot. Oat-0 significantly reduced the total nitrogen content of the soil, while there was no significant effect of the other treatments. O2P1 significantly out-yielded all control groups; however, it was not significantly different from fertilisation treatments. Intercropping with field pea did not significantly increase the cost of production of dry matter, crude protein, or dry matter digestibility compared to control groups. Intercropping with field pea significantly reduced the carbon footprint, acidification, eutrophication, and human toxicity footprint compared to the control groups. Therefore, oat–field pea intercrops are recommended for the production of high-quality forage at low N input with reduced environmental impact.

Nitrogen Fertilization Improves Growth and Bioactive Compound Content for Salvia miltiorrhiza Bunge

Salvia miltiorrhiza B., an herb used in traditional Chinese medicine, has been widely used to prevent and treat cardiovascular and other diseases. Currently, the majority of medicinal plants used in the US are imported from foreign countries, which involves transportation, quality control, and other issues. The objective of this study was to investigate the effect of nitrogen fertilization on growth and content of tanshinone I, tanshinone IIA, cryptotanshinone, and salvianolic acid B for Salvia miltiorrhiza B. in Mississippi. Plants were fertilized with one of five nitrogen (N) rates (0, 2, 4, 6, or 8 g N/plant from NH4NO3). Plants were harvested in November 2020 and 2021. Plants treated with 8 g N had higher plant growth index, leaf SPAD value, shoot and root number, shoot and root weight, maximum root length and diameter, shoot: root ratio, N concentration in root, and content of bioactive components compared to plants treated with 0, 2, 4 g N. Plants receiving 6 g N had similar shoot number, maximum root length, maximum root diameter, root weight and content of bioactive components compared to plants receiving 8 g N. However, plants receiving 6 g N had higher photosynthetic activity compared to plants receiving the higher N rate. Higher N rates increased plant growth and content of tested bioactive compounds.

Yield Prediction Models for ‘Royal Gala’ and ‘Fuji Suprema’ Apple Varieties Cultivated under a Subtropical Climate

Nitrogen (N) effect on crop yield depends on several factors such as soil type, climatic characteristics and orchard management, including plant density and N fertilization. These variables can be used to develop yield prediction models, which are scarce in the horticulture sector. This study aimed to evaluate the effect of nitrogen fertilization, orchards and cultivars and to predict the yields of ‘Royal Gala’ and ‘Fuji Suprema’ apples cultivated in a subtropical climate under different soil N availabilities. During the four seasons, nitrogen fertilization was applied a rates of 0, 25, 50, 100 and 150 kg N ha−1 year−1 for ‘Royal Gala’ and ‘Fuji Suprema’ apples located in southern Brazil. Yield, average fruit weight and leaf and fruit pulp N concentration were evaluated. Yield prediction models were developed based on the following variables: concentration of N in leaves and fruits, air temperature, chilling units, relative humidity and rainfall. “Cultivar” was the variable responsible for the greatest variation of yield, followed by “years/season”, and then the “orchard management. The N rates applied in the four seasons did not predict crop yield. In the model, “orchard” was the greatest determinant for leaf N concentration, and “season” was the main determinant for fruit-pulp N concentration. Mathematical model (3), based on leaf and fruit pulp N concentration, and certain climatic variables (minimum air temperature, annual rainfall and chilling hours &lt; 7.2 °C) had the greatest potential for predicting yield in orchards of ‘Royal Gala’ and ‘Fuji Suprema’.

Combined Effect of Nitrogen and Phosphorus Fertilizer on the Activity of the Nitrate Reductase Enzyme in Different Wheat Cultivars

Some characteristics of nitrogen metabolism were observed in the flag leaf on the main branch of wheat (Triticum aestivum L. and Triticum durum L.) In the current study, nine varieties were chosen and planted as test crop using split plot design and replicate at three times, with nutrient dose as the main plot and varieties as the sub plot treatment cultivated at three different soil nitrogen and phosphorus levels (0, 60, and 120 kg/hac) and (0, 30, and 60 kg/hac). These nitrogen and phosphorus levels were handled using four different treatments, where T1 served as the control, T2 as the nitrogen and phosphorus dose at its optimal level, and T3 as the half-nitrogen and full-phosphate fertilizer doses. Fertilizer dosages of T4 that were half nitrogen and half phosphorus were studied. Flag leaf blades were seen to be engaged in NO-3 assimilation. The flag leaf blade had the highest nitrate reductase activity, free amino acid content, and soluble protein content among all the leaf blades. The activity of nitrate reductase was markedly increased by the addition of nitrogen to the soil. The presence of substrate-dependent enzyme activity was demonstrated inflag leaf tissue. A coincidental association between enzyme activity and the buildup of reduced nitrogen in the plant shown the rise in nitrate reductase activity in response to more nitrogen and the increase vegetative reduced nitrogen. A substantial positive connection was discovered between nitrate reductase activity (expressed as molesN/hac.each season) and grain nitrogen (kg N/hac) at maturity because the transfer of vegetative nitrogen to the grain was homogeneous across treatments. Additionally, there was a strong and positive correlation between seasonal nitrate reductase and grain yields (kg/hac.). In cultivars resistant to lodging, maintaining nitrate reductase activity during the reproductive period might boost grain protein production and avoid the decrease of grain protein percentage that is usually seen when grain yields are high.

Effect of Irrigation, Nitrogen Fertilization and Amino Acid Biostimulant on Proximate Composition and Energy Value of Pisum sativum L. Seeds

The study investigated the impact of biological and agricultural conditions on the chemical composition and energy value of pea seeds for poultry feed. In the experiment, the species assessed was pea (Pisum sativum L.), a determinate form, cultivar (cv.) Cysterski. During the field experiment, the response of peas to the following experimental factors was assessed: first factor—irrigation (yes, no), second factor—nitrogen fertilization (0, 20 and 40 kg N·ha−1), third factor—amino acid biostimulant (yes, no). In both years of experiments, representative seed samples were collected, in which the chemical composition was assessed for the content of dry matter, crude protein, crude fat, crude fiber, and nitrogen free extract. Additionally, in order to assess the suitability of the evaluated pea seeds as poultry feed, the energy value expressed in the form of apparent metabolizable energy (AMEn) was estimated. The protein content in pea seeds increased after the application of the biostimulant, both with and without irrigation. Statistically significant differences in the crude fiber content in pea seeds were found under the influence of the interaction of irrigation and nitrogen fertilization. The use of the biostimulant significantly increased the energy value of pea seeds.

Effects of nitrogen fertilizer on protein synthesis, accumulation, and physicochemical properties in common buckwheat

Nitrogen (N) fertilization affects grain quality in common buckwheat (Fagopyrum esculentum Moench). But the effects of N fertilizer on various buckwheat protein parameters are not fully understood. This study aimed to investigate the synthesis, accumulation, and quality of buckwheat protein under four N application rates in the Loess Plateau, China. Optimal N application (180 kg N ha−1) improved yield, agronomic traits, and N transport and increased protein yield and protein component accumulation. Prolamin and glutelin accumulation first increased and then decreased with increasing N application. The relationships between the contents of protein components and the amount of applied N generally followed quadratic functions. Nitrate reductase and glutamine synthetase activities first increased and then decreased with increasing N levels. Optimal N fertilizer increased the waterholding capacity and thermal stability of buckwheat protein and reduced its emulsification capacity, but negligibly changed its oil-absorption capacity. Hydrophobic amino acids and glutelin content were the main factors affecting protein quality.

Does Drone Data Allow the Assessment of Phosphorus and Potassium in Soil Based on Field Experiments with Winter Rye?

The evaluation of the nutrient content in the soil, such as potassium and phosphorus, is very important, especially in precision agriculture, where the fertilizer rate should be adjusted to field variability in terms of nutrient content. Soil chemical analysis is time-consuming and expensive, and dense soil sampling is not always possible. In recent years, remote sensing methods have been used to assess the within-field variability of soil and crop nutritional status. The main aim of this study was to evaluate the relationship between UAV-derived spectral reflectance for winter rye in a long-term experiment for different fertilization with phosphorus and potassium. The study was conducted in 2022 in two field experiments in which winter rye was cultivated in monoculture and with crop rotation. The experiments were located in central Poland in Skierniewice. Statistical analyses were performed using univariate and multivariate methods, e.g., analysis of correlation, regression, and principal component analysis (PCA). The effect of phosphorus and potassium fertilization on the UAV-derived spectral reflectance of winter rye was weak, weaker in comparison to the effect of nitrogen fertilization. The effect of phosphorus and potassium fertilization on spectral reflectance was stronger in the experiment with monoculture than in the experiment with crop rotation. On the basis of correlation coefficients and PCA, negative relationships were proven between available soil potassium and spectral reflectance in the range of blue, green, and red bands and positive with red edge and near-infrared bands. The first principal component (PC1) was very strongly correlated with almost all spectral bands, either positively or negatively. The correlation of potassium and phosphorus content was very weak with PC1 in the experiment with crop rotation, while in the experiment with rye monoculture, the correlation was slightly stronger, indicating a stronger effect of nutrient deficiency in monoculture.