Total Nitrogen Yield Research Articles

Screening woody and shrub legumes for growth, nodulation and nitrogen-fixation potential in two contrasting soils

In order to identify for alley cropping new candidate species with high biomass and nitrogen-fixing potential, a screening study was conducted on ten woody and shrub legumes (Acacia auriculiformis, Albizia lebbeck, Gliricidia sepium, Leucaena diversifolia, L. leucocephala cv. K28 and cv. K636, Lonchocarpus sericeus, Cajanus cajan, Crotalaria juncea and Tephorsia candida) for 6 months using an acid Ultisol and a non-acid Alfisol. A wide interspecific variability of legumes appeared within soil types, and there were significant species-by-soil interactions for many parameters in this study. In the acid Ultisol, plant growth in height and grith, nodule numbers, nitrogen yield and N2-fixing potential were significantly (P = 0.05) lower than those in the Alfisol. While Albizia lebbeck was outstanding in both acid and non-acid soil conditions for most performance criteria, L. leucocephala cv. K28 was most sensitive to soil acidity with 41.7% of total nitrogen yield in the Ultisol relative to that accumulated in the Alfisol. In addition to L. leucocephala cv. K28 and G. sepium, the most common hedgerow species, A. lebbeck, L. leucocephala cv. K636, L. diversifolia on Alfisol, and A. lebbeck, L. leucocephala cv. K636, L. diversifolia, Tephrosia candida and Cajanus cajan on acid Ultisol, could be considered promising and thus, worthy of further site adaptability trials.

Response of nitrogen fixation, nodule activities, and growth to potassium supply in water‐stressed broad bean

Abstract Three‐week‐old nodulated faba bean plants were subjected to two levels of water stress (0.5 and 0.25 field capacity; soil water content of 20 and 10%) for five weeks. Half of the stressed plants was treated with potassium chloride (KC1) at 10 (K1) and 150 mg (K2)/kg soil at the beginning of water deficit. Nodulation was examined and some nodule activities were assayed. Nodulation, nitrogenase activity, total nitrogen (N), and dry matter yield were significantly decreased by increasing stress but were significantly higher with the two levels of potassium (K) supply. Leghaemoglobin and protein contents of cytosol as well as nodule protease and invertase were severely depressed by drought stress. Soluble carbohydrate contents of nodules, however, was significantly increased. Protein and leghaemoglobin contents and enzyme activities were greater with K fertilization but less soluble carbohydrate was accumulated. The results indicate that K supply, particularly at the 150 mg/kg soil level, increased faba bean resistance to water stress.

Evolution and reaction of coal fuel nitrogen during rapid oxidative pyrolysis and combustion

An arc-jet fired entrained-flow reactor has been used to study the evolution and reaction of fuel nitrogen during the rapid oxidative pyrolysis and combustion of two narrowly sizegraded pulverized coals: Montana Rosebud subbituminous and Pittsburgh #8 HVA bituminous. Tar released by the Pittsburgh coal undergoes rapid secondary decomposition in the presence of ≈900 ppm background O 2 , partitioning into gaseous products and soot. The characteristic time for tar decomposition ranges from 16 msec at 1325 K to only 5 msec at 1625 K. The soot yeild reaches an asymptote at 1400 K, representing 30% of the total volatile yieldsoot nitrogen represents 30% of the total volatile nitrogen yield at 1200 K, and 20% at 1630 K. The remainder of volatile nitrogen is initially released to the gas phase as HCN. Pyrolysis of the Rosebud coal yeelds gaseous products, with fuel nitrogen released primarily as HCN. During combustion of the Rosebud coal under single particle conditions at oxygen concentrations as low as 0.5%, virtually all of the evolved fuel nitrogen is converted to NO. In contrast, 45% of evolved fuel nitrogen is converted to N 2 during combustion of the Pittsburgh coal under similar conditions. Combustion studies at 5% O 2 reveal significantly higher NO levels for 35 μm vs 68 μm Pittsburgh coal. Rapid and early removal of NO added to the reactor is observed to qualitatively follow the overall tar/soot yield. Heterogeneous reduction of NO on soot is a possible explanation for the effect of both coal type and particle size on N 2 formation.

OPTIMIZATION OF ENZYMATIC HYDROLYSIS OF CANOLA MEAL WITH RESPONSE SURFACE METHODOLOGY

Hydrolysis of Alcalase 0.6L of canola meal increased its soluble protein content, thereby reducing fermentation time necessary for production of a condiment similar to soy sauce. Using soluble nitrogen content of the hydrolysate as a criterion, and with the aid of response surface methodology, optimum conditions for the enzymatic reaction were: 69°C, pH 9, enzyme/substrate ratio of 0.31:1 (v/w), meal/solvent ratio of 1:10 (w/v) and reaction time of 2 h. The second order polynomial equation used to calculate the total soluble nitrogen yield (y) from a combination of temperature (x1), pH (x2) and enzyme/substrate ratio (x3) was y = 0.479 + 0.0083x1+ 0.00077x2+ 0.011x3− 0.015x12− 0.02x22− 0.023x32+ 0.012x1x2+ 0.0051x1x3+ 0.00073x2x3. The canonical form of the equation used to demonstrate the nature of the response surface was y = 0.4813 − 0.01604w12− 0.02188w22− 0.02528w32 where w1, w2 and w3 are the axes of the response surface. The experimental result of total soluble nitrogen obtained under optimum conditions for enzymatic reaction was 0.4882, which closely agreed with the calculated yield of 0.4813.

Studies on persian clover (Trifolium resupinatum)

Yields of green fodder, dry matter and nitrogen were adversely affected by an increase in the harvesting interval of Persian clover from 40 to 100 days. The optimum harvesting interval which gave maximum yield of green fodder (86.6 ton/ha) and dry matter (11.2 ton/ha) was 30 days. The maximum yield of total nitrogen (423 kg/ha) was obtained when the harvesting interval was 20 days.

Field evaluation of N2-fixation and N-utilization by phaseolus bean varieties determined by15N isotope dilution*

Differences in N2-fixation byPhaseolus vulgaris bean cultivars were successfully evaluated in the field using15N isotope dilution technique with a non-fixing test crop of a different species (wheat). The Phaseolus cultivars could have been similarly ranked for N2-fixation capacity from either seed yield or total nitrogen yield, but the isotope method provided a direct measure of N2-fixation and made it possible to estimate the proportion of fixed to total nitrogen in the crop and in plant parts.

Effects of rate and timing of nitrogen dressings on grain yield formation of winter wheat (T. aestivum L.)

A field experiment with the winter wheat cultivar Donata was carried out on a fine-textured river clay soil in 1978. The rates of nitrogen dressing ranged from 0 to 160 kg N per ha and were split over from one up to three application times: autumn, early spring and late spring. Total above-ground dry matter and grain dry-weight yields ranged from 9.1 to 13.7 tons per ha and from 4.17 to 6.35 tons per ha, respectively. Late top-dressings increased the harvest-index, whereas an autumn dressing had the opposite effect. Number of culms per m2, grain weight (mg) and grain number per m2 increased from 350 to 430, from 35.5 to 36.8 and from 11 680 to 16 980, respectively, as the nitrogen dosage was raised from 0 to 160 kg N per ha. The linear rate of grain growth ranged from 111 to 172 kg dry matter per ha per day with nitrogen doses from 0 to 160 kg N per ha. Differences in rate of grain growth per unit area were mainly related to number of grains per m2. The association between grain number and grain yield was reflected by a correlation coefficient of 0.97 (n = 32). A higher level of nitrogen dressing enhanced the leaf area index and leaf area duration. However, we could not derive an effect of nitrogen on the duration of grain growth. Total nitrogen yield ranged from 71 to 166 kg N per ha and grain nitrogen yield from 54 to 122 kg N per ha with nitrogen dosages of 0 and 160 kg N per ha, respectively. The nitrogen concentration of the grains varied between 1.3 and 2.0 N. An autumn dressing of 40 kg N per ha generally showed only minor effects on yield and yield components. Top dressings during spring resulted in a higher recovery and efficiency of the applied nitrogen. Therefore, it may be concluded from this experiment and literature that on fertile soils an autumn dressing of nitrogen will not be economical, but split-dressings in spring are very beneficial. In particular, a late nitrogen application during the boot stage increased grain number, harvest-index and grain yield as well as protein concentration of the grain.

Dinitrogen fixation — acetylene reduction in soybeans during the reproductive growth period

In a greenhouse pot oulture experiment, a dinitrogen (N2) fixing — acetylene reduction activity profile was examined in detail as affected by plant age. Total [μmol C2H4 root-1 h-1] and speoifio nitrogenase [nmol C2H4 (mg nodule d. wt.)-1 min-1] activities peaked 63 days after sowing, near the end of flowering. The nitrogenase activities, nodule dry matter accumulation, top dry matter accumulation, and total nitrogen yield in the top dry matter were found to be highly correlated.

Agronomic studies on pigeon pea (Cajanus cajan (L.) Millsp.) III.* Responses to defoliation

Two early-maturing and two late-maturing accessions of Cajanus cajan grown in the field for 161 days were defoliated to 90 cm 'stubbles' every 4,8,12 or 16 weeks over a period of 72 weeks. Evidence from total and seasonal dry matter and nitrogen yields, stand survival, and stubble yield at the termination of the experiment suggested that 8- and 12-week defoliation frequencies could be successfully integrated to incorporate cattle grazing and forage and seed production into a single management system. The late-maturing accessions were shown clearly to be better adapted to cutting, provided that basal green leaves always remained on the stubble. Defoliation of the accession UQ50 to reduce plant height to facilitate subsequent harvesting led to a reduced annual seed yield. The first seed crop was lost, as 'topping' removed the reproductive material.

The effects of a wide range of nitrogen rates on some chemical constituents of the herbage from perennial ryegrass swards with and without white clover

SummarySelected herbage samples from a 6-year experiment in which nitrogen rates between 0 and 897 kg/ha were applied annually on perennial ryegrass swards were analysed for nitrate-nitrogen, true-protein and non-protein nitrogen, water-soluble carbohydrate, potassium and sodium content and for amino acid composition. The nitrate-nitrogen content of the herbage increased with increasing nitrogen rate from 224 kg/ha upwards, but the potentially toxic level of 220 mg/100 g dry matter was not reached until the annual nitrogen rate was about 560 kg/ha. On average, at the 897 kg nitrogen/ha rate the non-protein nitrogen content had increased to 27·5% of the total nitrogen yield, and 40·3% of the non-protein nitrogen yield consisted of nitrate nitrogen. Nitrate content was shown to be a sensitive indicator of the level of nitrogen nutrition of the herbage, the optimum nitrogen rate for dry-matter production coinciding with a nitrate-nitrogen content of approximately 100 mg/100g dry matter. The amino acid composition of the herbage varied little with either the rate of nitrogen or the date of cutting. It was demonstrated that, on average, a 1% unit increase in the crude-protein content of the herbage was accompanied by a 1% unit decrease in the carbohydrate content. The sodium content of the herbage increased with increasing nitrogen rate up to between 448 and 560 kg/ha, but the potassium content showed little variation.

Effects of Temperature and Nitrogen Supply on Four Nitrogen Fractions in Barley1

AbstractDistribution of four nitrogen fractions in tops and roots of 4‐ and 8‐week‐old barley (Hordeum vulgare L.) plants as influenced by two rates of nitrogen and three ambient temperatures during the latter half of growth period was studied in pot experiments. All plants were initially grown at 15.6 to 18.3 C for 4 weeks under two nitrogen treatments. Temperature variables were established on the plants during the last 4 weeks of growth. Temperatures tested in two sets of experiments were 7.2 to 8.9 C and 15.6 to 18.3 C, and 15.6 to 18.3 C and 26.6 to 27.7 C. Samples were analyzed for total, alcohol‐insoluble, alcohol‐soluble, and nitrate nitrogen. Highest dry matter was produced at 15.6 to 18.3 C. The 400‐mg N/pot yielded more total, alcohol‐insoluble, alcohol‐soluble, and nitrate nitrogen than the 20 mg N/pot. Yields of total and protein nitrogen in plants were approximately proportional to yield of dry matter, and percent total nitrogen in plants was inversely related to yield of dry matter. Alcohol soluble nitrogen yield was greater in plants grown at higher ambient temperatures in both experiments. In plants supplied with 400 mg N/pot, an above optimum temperature (26.6 to 27.7 C) caused a significant portion of the total nitrogen to be in alcohol‐soluble form. A large part of this alcohol‐soluble nitrogen was nitrate nitrogen. This alcohol‐soluble nitrogen is highly mobile and can be easily translocated to grain. These results corroborate field observations that temperatures above 27 C during the heading stage of barley plant restrict grain yields, even though protein percent remains high.

Yields of protein extracted from irrigated lucerne

Abstract When grown under irrigation in Canterbury, New Zealand, lucerne whole herbage gave total nitrogen yields and leaf and stem percentages which were similar for 5-weekJy (preflowering) harvests and early-flowenng harvests. Yields of extractable protem were also similar. although total herbage dry-matter yields were significantly higher from the longer intervals between harvests (195q kg/ha protein from 17 200 kg/ha dry herbage at preflowenng stage; 1880 kg/ha protem from 21 340 kg/ha dry herbage at early-flowering stage). Extractable protein yielded by herbage cut at 4-weekly intervals to a stubble of 10 em length was similar to that obtained from a crop cut less frequently and to a shorter stubble. Total N yield of lucerne was higher when the crop was grazed at 5-weekly intervals than when it was cut at the same mtervals. The yield of extractable protein from a treatment which was cut at 5-weekly intervals, then stocked. with sheep fed chopped green lucerne ad lib. on the. same area for the subsequ...

Analysis of Yield-Determining Process and Its Application to Yield-Prediction and Culture Improvement of Lowland Rice : XCII. Possibility of increasing yield and nutritional value of rice protein by nitrogen dressing

In the previous paper, it was found that top dressing with nitrogenous fertilizer at full heading stage increases their percentage of ripened grains and results in an increase in yield. On the other hand, it is known that the protein content of rice is increased by the application of nitrogenous fertilizer after heading stage. Based on those results, the present experiments were carried out to prove the possibility of increasing the protein yield and the nutritional value of rice by nitrogen dressing. Basal dressing and top dressing at panicle formation stage did not always affect the total nitrogen content ( : protein content) but top dressing at full heading stage increased the total nitrogen content by 15∼30 per cent. In the case of increasing not only the total nitrogen but the grain yield by top dressing at full heading stage, the total nitrogen yield was greatly increased by the interaction. With respect to a given quantity of top dressing after full heading stage (2∼8 Ng/m2), it was shown that the more the fertilizer applied, the more the total nitrogen content was increased. When an identical amount of the dressing was applied in the period from full heading stage to 30 days after it, it was the more effective at the nearer stage to full heading. The total nitrogen was less in milled rice than in brown rice and the decreasing rate of total nitrogen by milling was lower in the brown rice of high total nitrogen content increased by top dressing at full heading stage. This finding indicates that the increased protein is stored in the endosperm. The total nitrogen content in both the brown and the milled rices showed negative correlations with lysine and methionine contents to 16g total nitrogen but positive correlations with lysine, threonine and methionine contents on dry matter. As the results, it is presumed that top dressing at full heading stage serves to increase the protein content and the nutritional value of rice, and also the protein yield in case of the percentage of ripened grains being increased.

Development of proteolytic enzymes in growing papaya fruit

Latex samples, collected from the same papaya fruit at fixed time intervals until the fruit ripened, were freeze-dried. The yield of latex, total nitrogen and protein composition, as well as proteolytic activities, were determined. The latex samples, tapped from fruit during its development, were chromatographed on hydroxylapatite: the resulting chromatograms show the change in proteinase content with fruit development. The overall proteolytic activity in the latex of young fruit is noticeably less than in more mature fruit.

The response of some barley varieties to irrigation and nitrogen fertilizer

SummaryFour varieties of barley, selected for characteristics which could have value in a barley variety intended primarily for animal food, were compared with the variety Proctor under two levels of irrigation and two levels of nitrogen fertilizer. The exotic varieties yielded less grain and total dry matter than the adapted varieties, but differed in their response to irrigation. This difference was due chiefly to the ability to form extra ears when irrigated and the other yield components were less affected. Nitrogen fertilizer did not affect yield, although more ears were formed in the highlevel than the low-level treatment. The yield of nitrogen in the whole plant and in the yield of grain nitrogen were increased by high-nitrogen fertilizer and one of the exotic varieties was found to be capable of high yields of both grain nitrogen and total nitrogen, but there were no varietal differences in the response to nitrogen fertilizer.The varietal differences in response to irrigation are briefly discussed and related to development and possible drought resistance. The nitrogen yield of the grain is analysed in terms of total nitrogen uptake and distribution within the plant and the possibility of using the variation in these characteristics in a breeding programme is raised.

Radiolysis in the adsorbed state. II. N2O adsorbed on silica gel and zirconia

The 60Co γ-radiolysis of N2O adsorbed on silica gel and zirconia has been studied. In both systems a large fraction of the energy absorbed in the solid is able to cause decomposition of the N2O. For the silica gel – N2O system, studies with electron scavengers have shown that on gels degassed at low temperatures, electrons are precursors for a large fraction of the yield and about 1 G unit of nitrogen is produced by other processes. The total nitrogen yield is smaller for gels degassed at high temperatures, but the yield of nitrogen produced by direct excitation stays constant at 1 G unit.Experiments using electron scavengers with the zirconia–N2O system have shown that direct excitation of the solid is responsible for most of the nitrogen yield at 7 G units on high surface zirconia. Studies of nitrogen yields on a number of zirconias showed that the range over which energy is transferred is about 50 Å.

The effect of wet season land treatment and nitrogen fertilizer on safflower, linseed, and wheat in the Ord River valley. 2. Safflower and linseed

Gila safflower and RR 204 linseed were grown under irrigation at Kimberley Research Station in the 1964 dry season after 6-months and 18-months clean and weedy fallows. Four levels of nitrogen fertilizer, as ammonium sulphate and as urea, were superimposed. Seed yield responses to nitrogen fertilizer up to 80 lb N an acre (safflower) and 160 lb N an acre (linseed) were obtained after weedy fallows, but after 18 months clean fallow neither crop showed a significant response to nitrogen fertilizer up to 160 lb N an acre. Ammonium sulphate was more effective than urea at equivalent rates of nitrogen per acre. The amount of nitrate-nitrogen in the top three feet of soil shortly before planting was related to the total nitrogen yield of linseed at maturity, which, in turn, was closely related to seed yield. Increases in seed yield of linseed with clean fallowing and nitrogen fertilizer were largely the result of increases in bolls per plant and 100-seed weight.

Effects of the Ratio of Calcium to Potassium in the Nutrient Medium on the Growth and Alkaloid Production of Atropa belladonna

The increase of calcium/potassium ratios in nutrient solutions reduces growth of belladonna plants. This is evident in the reduced elongation of all stems, particularly the sympodial flowering branches, and in the fresh and dry weights of all plant parts. There appears to be a concurrent increase in the proportion of leaf to total plant at the expense of stem and root. The increase in calcium/potassium ratio results in higher yields of total nitrogen and alkaloids.

Isotopic studies on the uptake of nitrogen by pasture plants. III. The uptake of small additions of 15N-labelled fertilizer by Rhodes grass and Townsville lucerne

Small additions of (15NH4)2SO4 and K15NO3 were used to investigate the nitrogen economy of Townsville lucerne (Stylosanthes humilis H.B.K.) and Rhodes grass (Chloris gayana Kunth.) grown separately and together in pots. Rhodes grass reduced the total yield of nitrogen per plant in associated Townsville lucerne to about half that of Townsville lucerne in pure stand. It appears that the Rhodes grass seedlings competed strongly with Townsville lucerne for available soil nitrogen during the first 5 weeks of the experiment. When the two species were grown together, Rhodes grass took up about 20 times as much 15N as the Townsville lucerne during the first 9 weeks, and about 8 times as much between 9 and 13 weeks after sowing. This ratio was the same for (15NH4)2SO4 as for K15NO3. When the two species were grown separately they took up equal amounts of 15N between 9 and 13 weeks after sowing. Estimates of soil nitrogen uptake at 5 weeks showed that 47% of the nitrogen in the Townsville lucerne growing with Rhodes grass had come from the soil. At 9 weeks the cumulative uptake of soil nitrogen by this Townsville lucerne was only 6%, and at 13 weeks only 3%, of its total nitrogen yield. No significant transfer of unlabelled nitrogen from legume to grass was detected. Attention is drawn to the assumption used in calculating uptake of soil nitrogen by the legume. It is suggested that this tracer technique can be applied to 15N experiments in the field.

The effects of some grazed tropical grass-legume mixtures and nitrogen fertilized grass on total soil nitrogen, organic carbon, and subsequent yields of Sorghum vulgaris

Mixtures of some tropical legumes and Paspalum plicatulum (Michx) cv. Hartley, and stands of P. plicatulum were fertilized with urea at 100 and 200 lb nitrogen an acre a year, and were intermittently grazed by cattle over a period of four years. Soil analyses for organic carbon and for total soil nitrogen in the fourth year of the pasture phase revealed large treatment effects in three of the five replicates. These three replicates which were on a podsolic soil were lower in fertility than the remaining two on a latosolic soil. Soil nitrogen at the 0-3 inch depth in the high nitrogen treatment, and in two Phaseolus atropurpureus D.C. treatments was significantly higher than the control (P<0.05). Organic carbon at the 0-3 inch depth was significantly higher than the control (P<0.05) in the nitrogen treatments and in one of the P. atropurpureus treatments. For both soil nitrogen and organic carbon the Lotononis bainesii Bak. treatment did not differ from the control. There was no significant difference between treatments for soil nitrogen or organic carbon at the 3-6 inch depth though trends were similar to those at 0-3 inches. Organic carbon and nitrogen were closely correlated for all treatments at both depths, and there were no significant differences in the C : N ratio in any treatment. Yields of sorghum grown as a test crop after the pastures were significantly correlated with soil nitrogen values in the three low fertility replicates. A high correlation (r = +0.976) also existed between yields of nitrogen obtained in the pasture phase and test crop yields of nitrogen for all treatments except L. bainesii. Reasons for the apparent lack of improvement in soil nitrogen and carbon on the higher fertility replicates and for the poor test crop yields following L. bainesii are discussed.