The economic impact of future biological nitrogen fixation technologies

The economic impact of some future biological nitrogen fixation technologies are estimated using AGSIM, a dynamic, partial equilibrium, econometric model of the U.S. agricultural sector. Five separate scenarios were modeled: (1) legumes fix more nitrogen, (2) legumes fix more nitrogen with an increase in legumes yields of 10 percent, (3) nitrogen fertilization requirements on all crops are reduced 50 percent with no yield changes, (4) total elimination of nitrogen fertilization and (5) total elimination of nitrogen fertilization and non-legume yields decrease 10 percent. Results indicate that biological nitrogen fixation technologies have a high value to society. Increasing the efficiency of legumes to fix nitrogen may have an annual benefit of $1,067 million while decreasing nitrogen fertilization by 1,706 thousand tons. Total elimination of nitrogen fertilization of the crops has an annual benefit of$4,484 million.Crop Production/Industries,

Effects of Nitrogen Fertilization on Monoterpenes of Jack Pine Seedlings and Weight Gain of Jack Pine Budworm (Lepidoptera: Tortricidae)

Nine-month old jack pine (Pinus banksiana) seedlings were grown in a greenhouse under four nitrogen fertilization regimes. Levels of total nitrogen and five monoterpenes in new foliage were measured. Fertilization resulted in four significantly different levels of foliar nitrogen; means ranged from 1.8-4.5 percent dry weight. Contrary to predictions of resource availability theory, seedlings grown under the highest fertilization regime had higher foliar monoterpene levels than seedlings in the other treatments. Newly molted, sixth-instar female jack pine budworm (Choristoneura pinus pinus [Lepidoptera: Tortricidae]) larvae were allowed to feed for four days on new foliage of the seedlings. Larvae that fed on low-nitrogen seedling gained less weight and process more vegetation than did larvae on high- nitrogen seedlings. Larval weight gain was positively related to foliar nitrogen

Nitrogen balances in Dutch organic greenhouse production

The organic greenhouse production in the Netherlands is limited with regard to the number of growers, but plays an important role in EU organic greenhouse production. In the high-technology greenhouses a high production level is realized but nitrogen balances of this production system have been questioned. In order to document and improve the nitrogen balance, the production of seven greenhouses was monitored and soils were repeatedly analysed. The model “Bemestingsrichtlijn biologische kasteelten” (Fertilization Guide Organic Greenhouse Production) has been developed to simulate nitrogen availability and to fine-tune manure applications to crop demand. In the course of four years the overall nitrogen surpluses decreased sharply, but due to the observational character of the research no statistical analyses can be made. Part of the high surpluses in the first years can be explained by initial investments in soil organic matter. Calculation of the dynamic balance gives more possibilities to fine-tune farmers’ fertilization strategies. Growers that followed the model-based advise for manure application, realized a substantial reduction of nitrogen surpluses

The Effects of Nitrogen Fertilization and Deficit Irrigation Practices on Tomato Growth and Chlorophyll Concentration

Irrigation and fertilization are absolutely necessary in order to increase productivity in agricultural production. Water is the most important source of life on the earth. All living things need absolute water so that they can continue plants life. The fact that the nutrients present in the soil can complete the natural cycle is completely dependent on the water cycle. Irrigation is the amount and time required for the root zone of the plant in soil, which is needed by the plant and cannot enough by precipitation in agriculture. This study was carried out in the farmer\u27s greenhouse conditions between 2004-2005 years. Three different doses of nitrogen (N1:75 ppm N, N2:150 ppm N, N3:225 ppm N) were applied to the tomato plant grown in the greenhouse. S1:100% full irrigation, S2:50% irrigation according to pot capacity. The study was based on a trial randomized block design with 3 replications. At the end of 2 years, the results gave us; the best plant growth was measured with N3S1 an average height by128 cm. The worst plant height was obtained from N1S2 an average height by 88 cm. Plant body diameter has been found between 0,82cm and 0,54cm. Irrigation practices were more effective to total chlorophyll content than the fertilization practices. As a result, the deficit irrigation has also developed as well as full irrigation. Deficit irrigation and nitrogen fertilizer increased crop yield in arid regions.It is suggested that irrigation water can be reduced and adequate fertilization can be increased crop production in arid regions

Nutrient Limitation of Algal Growth in Fishery Lakes

This study investigated the effect of nutrient addition on algal growth in three United States Forest Service lakes for fishery management in Arkansas. In fishery managed lakes, fertilization works by manipulating algae growth, a basal food resource in lakes, to promote the growth of the fish population. For the nutrient addition experiments, water was collected from each lake in cubitainers and spiked with nutrients; the treatments included the control, nitrogen (+N), phosphorus (+P), and nitrogen and phosphorus (+N +P). When algal growth was visually observed, a water sample was collected from each cubitainer and analyzed for chlorophyll-α. The results showed that lakes were co-limited by nitrogen and phosphorus, and generally continued to be after fertilization. The data on the phytoplankton’s nutrient limitations provided the US Forest Service with information that can be used to develop a fertilization plan. Algal cells typically require between 10-20 mole of N per mole of P to promote growth, however, some of the fertilizers used by the USFS fall outside this range. The USFS needs to be consistent and use a balanced fertilizer (10-20:1) on all their lakes. Further research should also be performed to optimize the amount of fertilizer applied to each lake

Herbage Accumulation and Mass in Massai Grass Plots Mixed with Forage Peanut and Fertilized with Nitrogen

The objective of this work was to evaluate herbage accumulation and mass during the growing season of Massai grass mixed with peanut forage and fertilized with nitrogen. The work was carried out at Federal Rural University of Rio de Janeiro, Brazil, from 11/2021 to 03/2022. A randomized block experimental design was used, in plots of Massai grass Megathyrsus maximus, in a factorial arrangement, with seven replications. Four treatments formed by the combination of the presence or absence of Archis pintoi and nitrogen fertilization (0 and 50 kg ha-1 of N). Canopy heights of the plots were evaluated weekly and when they reached values of about 50 cm two samples were collected and the total herbage accumulation and mass were calculated. The treatments without nitrogen fertilization and legume had the lowest herbage accumulation and mass (5,080 and 2,060 kg ha-1 of DM, respectively), when compared to the plots that had nitrogen fertilization and legume. The treatments with or without legume but with nitrogen fertilization had the same herbage accumulation and mass (9,775 and 2,630 kg ha-1 of DM, respectively). Thus, the presence of the legume resulted in greater herbage accumulation and mass in relation to those plots without legume and nitrogen fertilization. However, when nitrogen fertilization was performed no additive effect with the presence of the legume was observed, indicating that the nitrogen fertilization somehow inhibited the benefit of the legume on forage production. So, based on the short-term results obtained, the use of nitrogen fertilization or the use of forage peanuts should be done separately

EFFECTS OF RISK ON OPTIMAL NITROGEN FERTILIZATION DATES IN WINTER WHEAT PRODUCTION AS AFFECTED BY DISEASE AND NITROGEN SOURCE

Optimal fertilization dates were found for two nitrogen sources in the presence of two diseases for wheat farmers with different risk preferences. Risk was independent of fertilization date. Ammonium Nitrate and Urea-Ammonium Nitrate did not affect risk differently. Ammonium Nitrate applied on March 9 was optimal regardless of risk preferences.Crop Production/Industries,

Carbon dioxide level and form of soil nitrogen regulate assimilation of atmospheric ammonia in young trees.

The influence of carbon dioxide (CO2) and soil fertility on the physiological performance of plants has been extensively studied, but their combined effect is notoriously difficult to predict. Using Coffea arabica as a model tree species, we observed an additive effect on growth, by which aboveground productivity was highest under elevated CO2 and ammonium fertilization, while nitrate fertilization favored greater belowground biomass allocation regardless of CO2 concentration. A pulse of labelled gases ((13)CO2 and (15)NH3) was administered to these trees as a means to determine the legacy effect of CO2 level and soil nitrogen form on foliar gas uptake and translocation. Surprisingly, trees with the largest aboveground biomass assimilated significantly less NH3 than the smaller trees. This was partly explained by declines in stomatal conductance in plants grown under elevated CO2. However, unlike the (13)CO2 pulse, assimilation and transport of the (15)NH3 pulse to shoots and roots varied as a function of interactions between stomatal conductance and direct plant response to the form of soil nitrogen, observed as differences in tissue nitrogen content and biomass allocation. Nitrogen form is therefore an intrinsic component of physiological responses to atmospheric change, including assimilation of gaseous nitrogen as influenced by plant growth history