Research on the Influence of Irrigation Amount on Dynamic Changes and Accumulation of Soil Nitric Nitrogen under Film Hole Irrigation

2012 ◽  
Vol 518-523 ◽  
pp. 5292-5296 ◽  
Author(s):  
Feng Tai Guo ◽  
Tao Tao ◽  
Dong Juan Cheng ◽  
Ran Gao

Through the experiment of different Irrigation Amounts with urea applied, the paper studied the influence of Irrigation Amounts on soil nitric nitrogen dynamical changes under film hole irrigation and the nitric nitrogen content of the growing period was determined. The result showed: different irrigation amount in the profiles being 3cm and 8cm away from the film hole center, it appeared nitric nitrogen accumulation peaks, increased the irrigation amount promoted the transformation of urea, increased the transformed nitric nitrogen content and distribution of nitric nitrate and the risk of nitric nitrate leaching. In the profiles being 3cm away from the film hole center, the nitric nitrogen accumulation peak significantly reduced at harvest stage, but it reduced in the profiles being 8cm away from the film hole center at milky stage. The milky stage was the maximum period when the corn uptook nitrogen at different irrigation amount. Increased irrigation amount lower the accumulation content of nitric nitrogen near the film hole center after harvest, and higher the accumulation content of nitric nitrogen far away from the film hole center. Above researches could provide the basis for rational fertilization of farmland and nitrate environmental impacts on assessment.

1961 ◽  
Vol 33 (1) ◽  
pp. 159-168
Author(s):  
Pentti Hänninen ◽  
Armi Kaila

Calcium nitrate and ammonium nitrate limestone (»Oulunsalpietari») were compared as the nitrogen fertilizer for oats in 15 field trials and for barley in one trial. The trials were carried out in summers 1959 and 1960 in various places in Finland. The split plot technique was employed in order to reduce the variation as much as possible. In 1959 the amounts of nitrogen applied as these two fertilizers to the corresponding halves of the plots were 25 and 50 kg/ha. In 1960 also higher applications were used: 75 and 100 kg/ha of N. In three trials these fertilizers were compared both as a surface dressing and worked in. Visual observations suggested about 5—6 weeks after sowing a darker green colour in the stands treated with calcium nitrate as compared with the other half treated with ammonium nitrate limestone. These differences later disappeared. In some trials a higher nitrogen content of the plants from the calcium nitrate stands could be demonstrated during this period. The uptake of nitrogen by plants was regularly followed throughout the growing period. Owing to the large variation, usually, no statistically significant difference between the effect of the fertilizers could be detected. In a few cases the superiority of calcium nitrate could be demonstrated. No differences in the ripening could be found. In most trials there was a fairly regular tendency to higher yields and higher nitrogen content in the grain and straw produced by calcium nitrate. Yet, only in a few cases were the differences statistically significant at the five per cent level. Thus, it was concluded that on the basis of the results of these trials ammonium nitrate limestone and calcium nitrate may be considered practically equal as nitrogen fertilizers for oats. There was no difference in the yields of barley produced by these two fertilizers, but the nitrogen content of grains was significantly lower with ammonium nitrate limestone than with calcium nitrate. This may be worth further study in connection with the production of malting barley.


2001 ◽  
Vol 1 ◽  
pp. 81-89 ◽  
Author(s):  
Chwen-Ming Yang

Ground-based remotely sensed reflectance spectra of hyperspectral resolution were monitored during the growing period of rice under various nitrogen application rates. It was found that reflectance spectrum of rice canopy changed in both wavelength and reflectance as the plants developed. Fifteen characteristic wavebands were identified from the apparent peaks and valleys of spectral reflectance curves, in accordance with the results of the first-order differentiation, measured over the growing season of rice. The bandwidths and center wavelengths of these characteristic wavebands were different among nitrogen treatments. The simplified features by connecting these 15 characteristic wavelengths may be considered as spectral signatures of rice canopy, but spectral signatures varied with developmental age and nitrogen application rates. Among these characteristic wavebands, the changes of the wavelength in band 11 showed a positive linear relationship with application rates of nitrogen fertilizer, while it was a negative linear relationship in band 5. Mean reflectance of wavelengths in bands 1, 2, 3, 5, 11, and 15 was significantly correlated with application rates. Reflectance of these six wavelengths changed nonlinearly after transplanting and could be used in combination to distinguish rice plants subjected to different nitrogen application rates. From the correlation analyses, there are a variety of correlation coefficients for spectral reflectance to leaf nitrogen content in the range of 350-2400 nm. Reflectance of most wavelengths exhibited an inverse correlation with leaf nitrogen content, with the largest negative value (r = �0.581) located at about 1376 nm. Changes in reflectance at 1376 nm to leaf nitrogen content during the growing period were closely related and were best fitted to a nonlinear function. This relationship may be used to estimate and to monitor nitrogen content of rice leaves during rice growth. Reflectance of red light minimum and near-infrared peak and leaf nitrogen content were correlated nonlinearly.


2012 ◽  
Vol 49 (No. 3) ◽  
pp. 104-107 ◽  
Author(s):  
V. V Podrázský ◽  
I. Ulbrichová

The present study documents the effects of green alder [Alnus alnobetula (Ehrh.) C. Koch] on the uppermost forest soil layers in mountain areas, respectively in the summit part of the Jizerské hory Mts. Pedochemical characteristics of holorganic horizons in stands of this species, established in 1992 on a clear-cut caused by air pollution, were compared to the status of soils in stands of bog pine (Pinus rotundata Link.). Extreme site conditions and young age of both stand types resulted in low effects on the humus forms in the first decade. Despite of this, enrichment in total nitrogen content and tendency to acidification due to nitrate leaching were obvious and statistically significant in green alder stands.


2012 ◽  
Vol 28 ◽  
pp. 246-251 ◽  
Author(s):  
Hu Hao-yun ◽  
Jin Jie ◽  
Cheng Dong-juan ◽  
Gao Ran

2008 ◽  
Vol 19 (2) ◽  
pp. 173 ◽  
Author(s):  
L. MUSTONEN ◽  
E. WALLIUS ◽  
T. HURME

The effects various rates of nitrogen application on accumulation of dry matter and nitrogen in potato (Solanum tuberosum L.) were studied during a short growing period of 140–180 days, at MTT Agrifood Research Finland in 2000–2001. The treatments were 0, 60 and 120 kg N ha-1 and the potato cultivars tested were Van Gogh and Nicola. Four successive harvests were made during the course of the experiment to monitor changes in the accumulation of dry matter and nitrogen over the season. Applications of nitrogen substantially increased haulm dry matter accumulation and to an even greater extent their nitrogen contents. The highest dry matter values were generally registered at 120 kg N ha-1. Dry matter and nitrogen content of haulms started to decline during the later part of season and most nitrogen was relocated to tubers. The results suggest that an application of only 60 kg N ha-1 was sufficient to promote rapid canopy development and there were only small reductions in dry matter and nitrogen accumulation until late in the season when the canopy started to senesce as nitrogen supply diminished. Tuber yield, plant dry matter and nitrogen accumulation at maturity were related to crop nitrogen supply. Although application of the high rate, 120 N kg ha-1, resulted in a significant increase in dry matter accumulation, this was not reflected in the profit because the higher nitrogen application reduced dry matter content of tubers by 2.6% in 2000 and by 1.1% in 2001 relative to the use of 60 kg N ha-1. Apparent fertilizer nitrogen recovery values on a whole plant basis ranged from 53 to 75%. The proportion of fertilizer recovered in tubers clearly declined with increase in nitrogen supply.;


2020 ◽  
Vol 43 ◽  
pp. e46764
Author(s):  
Marcelo Curitiba Espindula ◽  
Giovana Menonci Rodovalho ◽  
Alaerto Luiz Marcolan ◽  
Iara Magalhães Barberena ◽  
Henrique Nery Cipriani ◽  
...  

This study presents an evaluation of the viability of using protected urea under different irrigation depths to reduce nitrogen losses caused by the volatilization of ammonia (NH3) under the conditions of the Southwestern Amazon. The study was carried out at the Experimental Station of Embrapa Rondônia, in the municipality of Porto Velho, Rondônia State, Brazil. The experiment was conducted in a Red-Yellow Latosol and arranged in a 5 x 6 factorial design consisting of a combination of five treatments (N sources) with six irrigation depths. The sources of N were as follows: 1) urea (45.5% N); 2) urea (44.3% N) + 0.15% copper and 0.4% boron; 3) urea (45% N) + NBPT; 4) urea (43% N) + sulfur (1%); and 5) control (without N). The irrigation depths were 0, 5, 10, 15, 20, and 25 mm. The results showed that, regardless of the use of urease inhibitors, an irrigation depth of 10 mm is suitable for incorporating urea into the soil and stabilizing N losses from NH3 volatilization. NBPT is the most efficient inhibitor under nonirrigated conditions. All N sources promote increases in the concentrations of nitric and ammonia nitrogen in the soil. In the first 15 days after fertilizer application, the highest concentrations of ammonium were in the 0 - 10 cm and 10 - 20 cm soil layers, and NBPT showed the highest ammonium content compared to that of the other sources in the 0 - 10 cm layer. The nitric nitrogen content in the soil was slightly influenced by the irrigation depth in the first 15 days after fertilizer application. However, the ammonia nitrogen content decreased exponentially with the increase in irrigation depth due to the movement of ammonia in the soil.


2009 ◽  
Vol 147 (6) ◽  
pp. 657-667 ◽  
Author(s):  
M. M. ACRECHE ◽  
G. A. SLAFER

SUMMARYWheat yield and grain nitrogen concentration (GNC; mg N/g grain) are frequently negatively correlated. In most growing conditions, this is mainly due to a feedback process between GNC and the number of grains/m2. In Mediterranean conditions, breeders may have produced cultivars with conservative grain set. The present study aimed at clarifying the main physiological determinants of grain nitrogen accumulation (GNA) in Mediterranean wheat and to analyse how breeding has affected them. Five field experiments were carried out in north-eastern Spain in the 2005/06 and 2006/07 growing seasons with three cultivars released at different times and an advanced line. Depending on the experiment, source-sink ratios during grain filling were altered by reducing grain number/m2 either through pre-anthesis shading (unshaded control or 0·75 shading only between jointing and anthesis) or by directly trimming the spikes after anthesis and before the onset of the effective grain filling period (un-trimmed control or spikes halved 7–10 days after anthesis). Grain nitrogen content (GN content; mg N/grain) decreased with the year of release of the genotypes. As the number of grains/m2 was also increased by breeding there was a clear dilution effect on the amount of nitrogen allocated to each grain. However, the increase in GN content in old genotypes did not compensate for the loss in grain nitrogen yield (GNY) due to the lower number of grains/m2. GN content of all genotypes increased (increases ranged from 0·13 to 0·40 mg N/grain, depending on experiment and genotype) in response to the post-anthesis spike trimming or pre-anthesis shading. The degree of source-limitation for GNA increased with the year of release of the genotypes (and thus with increases in grain number/m2) from 0·22 (mean of the four manipulative experiments) in the oldest cultivar to 0·51 (mean of the four manipulative experiments) in the most modern line. It was found that final GN content depended strongly on the source-sink ratio established at anthesis between the number of grains set and the amount of nitrogen absorbed at this stage. Thus, Mediterranean wheat breeding that improved yield through increases in grain number/m2 reduced the GN content by diluting a rather limited source of nitrogen into more grains. This dilution effect produced by breeding was further confirmed by the reversal effect produced by grain number/m2 reductions due to either pre-anthesis shading or post-anthesis spike trimming.


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