Petiole sap NO3-N testing as a method for monitoring nitrogen nutrition of potato crops

1997 ◽  
Vol 77 (2) ◽  
pp. 273-278 ◽  
Author(s):  
D. Waterer

Petiole sap NO3-N concentrations were tested as a means for monitoring crop nitrogen (N) status and N fertilizer responses in potatoes. An ion specific electrode was used to monitor sap NO3-N concentrations of three varieties of potatoes grown with differing amounts of N fertilizer in 1993–1995. Plots provided with varying amounts of fertilizer N applied prior to planting or as a split application were sampled on six occasions through the growing season. Sap NO3-N levels were positively correlated with petiole dry matter NO3-N levels. Petiole sap NO3-N levels reflected rates and timing of N fertilizer application. Sap NO3-N levels in the three cultivars showed similar changes with time after planting and increasing N fertilizer rates. However, sap NO3-N levels measured under a particular set of conditions were unique for each cultivar. The correlation between yields and sap NO3-N levels varied with the sampling date and cultivar. Recommendations were developed for critical sap NO3-N concentrations at various stages in the development of the three cultivars. Key words: Ion specific electrode, nitrate, petiole, nitrogen, tissue testing, Solanum tuberosum

1980 ◽  
Vol 95 (2) ◽  
pp. 471-485 ◽  
Author(s):  
D. J. Greenwood ◽  
T. J. Cleaver ◽  
Mary K. Turner ◽  
J. Hunt ◽  
K. B. Niendorf ◽  
...  

SUMMARYThe effect of level of N fertilizer on the composition, yield and quality of 21 crops was studied in experiments on adjacent sites of the same field to aid in the development of fertilizer recommendations.Yield of each of the crops first increased and then either remained the same or declined with further increases of N fertilizer. Interpretation by means of a simple model enabled response curves to be characterized by two parameters; one representing the beneficial component of the response and the other the detrimental component. Both varied greatly from crop to crop.The magnitude of the beneficial component of the response of most non-leguminous crops was largely determined by the potential demand of the crop for nitrogen; the exceptions were some root crops which responded less than would be expected on this basis. The adverse component was serious with root crops and those crops that are in the soil for only a short period. High levels of N increased the ratio of foliage to storage root dry weights even when total dry matter was unaffected. The changes were associated with a considerable increase in the % N in the dry matter of the roots.When crops were grown with their optimum levels of N fertilizer a simple linear. relationship between the mean %N in the dry matter and the total weight of dry matter per unit area covered all crops. Simple relationships also existed between total dry matter of non-leguminous crops and (a) the amount of N taken up by the crop from unfertilized soil, (b) the recovery of added fertilizer by the crop and (c) the beneficial component of the response of crops harvested before October.Percentage N in the dry matter at harvest was not a sensitive indicator of the extent to which plant growth was restricted by lack of nitrogen; a difference of 0·1% N in the plant material was associated with a 10% increase in yield.N fertilizer levels influenced the % dry matter and the incidence of crop disorders such as rotten roots and tissue discoloration, but the effects were seldom appreciable with practicable levels of fertilizer application.


2015 ◽  
Vol 42 (4) ◽  
pp. 599-605 ◽  
Author(s):  
A. Łotocki ◽  
W. Żelawski

Water culture and sand culture seedlings of Scots pine were investigated in respect to their reaction to ammonium or nitrate source of nitrogen nutrition. Photosynthesis, respiration, and dry matter production were studied in three and four months old plants. The results are preliminary but they have indicated that the effect of various form of nitrogen nutrition on gas exchange and growth rates could change during the growing season.


1985 ◽  
Vol 25 (1) ◽  
pp. 54 ◽  
Author(s):  
DL Lloyd ◽  
TB Hilder

The effects of a temperate annual legume, barrel medic (Medicago truncatula) cv. Cyprus, and five levels of fertilizer nitrogen (N), from 0 to 400 kg/ha.year, on the dry matter (DM) production and N economy of Makarikari grass (Panicum coloratum var. makarikariense) cv. Pollock, were investigated in a cutting experiment between 1973 and 1979. Each year, N fertilizer on grass alone increased both DM production and N uptake, up to N application rates of 200 and 400 kg/ha.year respectively. The mean annual effect of medic was to increase DM production and N uptake of associated grass each year by 90 and 130% respectively, and of the grass-medic system by 230 and 530%, respectively, for fertilizer rates between 0 and 100 kg N/ha.year. The increased DM production of associated grass occurred in summer and autumn; grass DM production was suppressed in spring, probably by competition with the medic. A trend for the DM yield of grass grown without medic to decline with time was most evident in the treatment without N fertilizer; in the comparable grass-medic pasture, grass DM production was as great in the sixth year as in the first. Medic DM yield varied with winter season rainfall. When the study concluded, the amount of N in the soil (0-10 cm depth) was higher after grassmedic than grass alone, except at the highest level of N fertilizer application. It was estimated that medic had fixed about 71 kg N/ha.year.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 672e-672
Author(s):  
Peter Bierman ◽  
Tom Wall

Inadequate N can reduce growth and yield, but excess N can be uneconomical and environmentally harmful. Our objective was to investigate the potential for using fertigation and on-farm plant-nutrient monitoring to improve the efficiency of N fertilizer use by bell peppers (Capsicum annuum L.). Two N fertilizer treatments were compared: 1) all N applied preplant and 2) one-third of the N applied preplant and the remainder injected into the drip-irrigation lines throughout the growing season. Total application rates were N at 118 kg·ha–1 for both treatments. Data were collected for total yield, marketable yield, and fruit size. Leaf and petiole samples were collected every 2 weeks and were used to monitor plant N status throughout the growing season. A Horiba/Cardy nitrate meter was used to measure nitrate concentrations in freshly-pressed petiole sap. A SPAD chlorophyll meter was used to measure leaf chlorophyll content and give an indirect measure of leaf N concentrations. Subsamples of leaves and petioles also were saved for conventional laboratory analyses. Whole (aboveground) plant samples were collected every 2 weeks, analyzed, and used to calculate differences in N accumulation. Suction cup samplers were installed at the 24-in soil depth and water samples collected every 1 to 2 weeks for nitrate analysis. Except for early in the growing season, petiole sap nitrate and leaf chlorophyll were higher in the fertigation treatment. Plant dry matter and total N accumulation also were much larger, but fertigation did not increase yield. Nitrate leaching was greater early in the season with 100% preplant N, but later in the season it was greater with fertigation. Data suggested that adequate plant N, reduced nitrate leaching, and equivalent yields are possible with fertigation at reduced N-rates compared to 100% preplant fertilizer applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mekuannet K. Belay

Appropriate selection of varieties based on agroecologies and application of the right amount and type of fertilizers based on crop requirements are crucially indispensable to maximize maize production. A field experiment was conducted for two consecutive years under main cropping seasons to evaluate the effect of blended NPS and N fertilizer rates on growth, yield components, and yield of open-pollinated maize varieties at the moisture stress area, eastern Ethiopia. The experiment was comprised of two lowland maize varieties, three blended NPS (50, 100, and 150 kg), and three N levels (43.5, 87, and 130.5 kg) ha−1 using a factorial arrangement under a randomized complete block design with three replications. The results showed that the leaf area index, thousand kernel weight, and biomass and grain yields were significantly influenced by the interaction effect of variety × NPS and N in the first growing season. The number of ears per plant, ear length, ear diameter, number of kernels per ear, and biomass yield were significantly affected due to variety in the second growing season. The maximum growth parameters and yield components were recorded from Baate and 150 kg blended NPS. Grain yield and harvest index were statistically affected by interaction effects of variety × NPS and N in both years. Therefore, the highest grain yield (9.7 t·ha−1) was produced from Baate at a combined application of 150 kg NPS and 130.5 kg N·ha−1. The partial budget analysis also confirmed that the highest net benefit (2,033.4 USD) with the highest marginal rate of return (3106.9%) was obtained at Baate variety where plants were fertilized with 150 NPS and 130.5 kg N·ha−1. In conclusion, an integrated application of 150 NPS + 130.5 kg N·ha−1 to Baate variety is agronomically optimum and economically realistic fertilizer level to get a higher grain yield in the study area.


1974 ◽  
Vol 14 (67) ◽  
pp. 237 ◽  
Author(s):  
TG Reeves ◽  
A Ellington

Results are presented from three experiments, on land being cropped for the third time after a ley period, in which the growth and nitrogen nutrition of direct drilled and conventionally cultivated and sown wheat was investigated. In 1968 and 1969 wheat growth from emergence to heading was superior on the cultivated plots but grain yields did not differ. In 1970 direct drilling increased wheat grain yield by 0.97 tonne ha-1. Nitrogen fertilizer application at seeding increased herbage dry matter and nitrogen content, fertile tiller production and grain yields on both direct-drilled and cultivated treatments. Soil mineral nitrogen levels at seeding were lower on cultivated plots than on direct-drilled plots, but incubation nitrogen was not different in any year. Direct drilling did not adversely affect mineralization of soil nitrogen, but it retarded early wheat growth.


1980 ◽  
Vol 60 (4) ◽  
pp. 1179-1189
Author(s):  
T. LAWRENCE ◽  
G. E. WINKLEMAN ◽  
F. G. WARDER ◽  
H. C. KORVEN

The effects of five times of irrigation, two times of N-fertilizer application and four rates of N-fertilizer application on the seed yield, dry matter yield, N, P, NO3-N, Ca, Mg, and K content and K/(Ca+Mg) ratio of Altai wild ryegrass (Elymus angustus Trin.), were studied from 1974 to 1977. No clear-cut methods to maximize the seed yield on irrigated land were found. Highest dry matter yields were obtained from grass given three irrigations and 400 kg N/ha per year. Spring applications of N fertilizer resulted in forage with a higher N content than fall applications. The N content of the forage increased with increasing levels of N fertilizer, whereas the P content of the forage was reduced by N fertilizer applications. Toxic levels of nitrates can be expected from spring applications of 400 kg N/ha. This danger was reduced if N fertilizer was applied in the fall. The Ca, Mg and K content increased with increasing levels of N fertilizer. The K/(Ca+Mg) ratio indicated that there was little danger of grass tetany problems in animals fed fertilized Altai wild ryegrass.


2020 ◽  
Vol 14 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Oluwaseyi I. Ogunboye ◽  
Aruna O. Adekiya ◽  
Babatunde S. Ewulo ◽  
Adeniyi Olayanju

Background: Since N fertilizer applied to maize (Zea mays L.) is prone to loss by leaching, it is important to derive an application time during the phenology of maize when the fertilizer is most efficiently and effectively used by the crop with minimal losses. Objective: Hence, experiments were carried out in 2014 at two locations in Osogbo southwest Nigeria to determine the effects of split application of N fertilizer on soil chemical properties, maize performance, and profitability. Methods: The treatments were: (i) control, (ii) 120 kg N ha-1 Applied at Planting (AP), (iii) two split applications (SA) of 120 kg N ha-1 {90 kg N ha-1 applied AP + 30kg N ha-1 at thirty Days After Planting (DAP) [90 + 30]}, and (iv) three SA of 120 kg N ha-1 {60 kg N ha-1 applied AP + 30 kg N ha-1 thirty DAP + 30 kg N ha-1 at tasselling[60+30+30]}. The four treatments were arranged in a Randomized Complete Block Design with three replicates. Results: Results indicate that at both sites, SA three times (60+30+30) has the most improved soil chemical properties, growth and yield of maize relative to other methods. The yield parameters increased in the order: control < 120 kg N ha-1 applied once < 90+30 < 60+30+30. Using the mean of both sites, 60+30+30 increased yield of maize by 15.3%, 37.1% and 138.2%, respectively compared with 90+30, 120 kg N ha-1 applied once and the control. Optimum returns were recorded by 60+30+30 with net return of ₦ 227,600 and a benefit cost ratio of 3.67:1 while the application of 120 kg N ha-1 applied once has a return of ₦ 157,200 with a benefit ratio of 2.9. These results show that farmers would benefit by making more profit by adopting the method of SA of N fertilizer three times (60+30+30). Conclusion: Therefore, for improved soil chemical properties, growth, yield and profitability of maize, N fertilizer application should be structured in accordance with this pattern of uptake to avoid losses by leaching and therefore ensure that N level in the soil is high at the critical stage of N demand.


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