scholarly journals Spectral sensors prove beneficial in determining nitrogen fertilizer needs of Urochloa brizantha cv. Xaraés grass in Brazil

2020 ◽  
Vol 8 (2) ◽  
pp. 60-71
Author(s):  
Helizani C. Bazame ◽  
Francisco A.C. Pinto ◽  
Domingos S. Queiroz ◽  
Daniel M. de Queiroz ◽  
Daniel Althoff

The objective of the present work was to evaluate the use of spectral sensors to determine nitrogen fertilizer requirements for pastures of Urochloa brizantha cv. Xaraés in Brazil. The experimental design was a randomized block design with 4 replications of 4 treatments: a control treatment (TT) without application of N; a reference treatment (TR) with N applied at a standard predetermined fixed rate (150 kg urea/ha/cycle); a treatment using GreenSeekerTM (TG) to determine N requirement by the canopy normalized difference vegetation index (NDVI); and a treatment using SPAD 502 (TS) to determine N requirement by foliar chlorophyll assessment. For treatments involving spectral sensors, N fertilizer was applied at half the rate of that in the reference treatment at the beginning of each cycle and further N was applied only when the nitrogen sufficiency index dropped below 0.85. The sensors used in the work indicated that no additional N fertilizer was required by these pastures above the half rates applied. Applying N at the reduced rates to the pastures was more efficient than the pre-determined fixed rate, as both sensor treatments and the fixed rate treatment produced similar total forage yields, with similar crude protein concentrations. All fertilized pastures supported similar stocking rates, while the sensor treatments used less N fertilizer, i.e. 75 kg urea/ha/cycle less than the reference plot. Longer-term studies to verify these findings are warranted followed by promotion of the technology to farmers to possibly reduce fertilizer application rates, improve profitability and provide environmental benefits.

2021 ◽  
Vol 24 (1) ◽  
pp. 77-87
Author(s):  
SS Keya ◽  
MG Miah ◽  
MA Rahman ◽  
MT Islam

Excess use of agrochemicals for intensive cultivation affects crop quality and destroys agro-ecosystems, and eventually creates health hazards. The study aims to investigate the effect of Gliricidia sepium (GS) tree leaf as suitable green manures for supplementing nutrient supply along with nitrogen (N) fertilizer to produce quality tomato and soil fertility improvement. A field experiment was conducted at the Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh, from November 2016 to March 2017. The experiment was laid out in a randomized complete block design (two factors) with three replications. There were nine treatment combinations with three levels of GS tree leaves (5, 10 and 15 t ha−1) and three doses of N (0, 50 and 100% of the recommended dose of fertilizer). The highest tomato yield was recorded in GS15×N100 treatment combination, which was 41.68% higher compared to the control treatment. Decreasing C: N ratio in increasing dose of GS and N treated plot indicated the quality of tree leaves that ensures faster decomposition and high nutrient release pattern of this species. Increasing rate of soil pH and cation exchange capacity (CEC) in different treatments as compared to initial soil showed soil fertility improvement. Overall, the results indicated that quality tomato could be grown successfully by the application of G. sepium tree leaves along with an appropriate amount of N fertilizer. Ann. Bangladesh Agric. (2020) 24(1) : 77-87


1987 ◽  
Vol 38 (4) ◽  
pp. 681 ◽  
Author(s):  
AS Hodgson ◽  
DA MacLeod

Foliar-applied nitrogen (N) fertilizer was investigated as a means of ameliorating the damage to cotton of waterlogging associated with extended furrow irrigation of a cracking grey clay. Dissolved urea was applied at 0, 5, 10 and 20 kg N ha-1 to the cotton foliage one day before furrow irrigations lasting 4, 8, 16 and 32 h. Treatments were repeated at three crop irrigations. Storms following the first two irrigations delayed the recovery from waterlogging and reduced treatment differences. However, foliar-applied N significantly increased late square and green boll numbers after the third irrigation, and produced more open bolls and heavier lint yields than the control treatment at harvest. Lint yields increased by 2.8, 5.9, 8.4 and up to 10.5 kg ha-1 per kg of foliar N applied before irrigations lasting 4, 8, 16 and 32 h, respectively. From this interaction it was concluded that foliar-applied N ameliorated the effects of waterlogging. Nevertheless, in the most severe waterlogging treatment, yield response to foliar N reached a limit, indicating that some other factor had become limiting.


2021 ◽  
Author(s):  
Maria Heiling ◽  
Mahdi Shorafa ◽  
Rayehe Mirkhani ◽  
Elden Willems ◽  
Arsenio Toloza ◽  
...  

<p>Nitrogen (N) fertilizer management is challenging due to the many factors and have low N use efficiency (NUE). Heavy N losses from soil reduce plant yield and have negative impacts on the environment. Nitrogen processes inhibitors, such as urease and nitrification inhibitors (UI and NI), are chemical compounds which reduce urea hydrolysis and nitrification respectively. By coating ammonium based chemical fertilizers with N process inhibitors allows N to stay in a more stable form of ammonium (NH<sub>4</sub><sup>+</sup>) thus minimising N losses as well as improving NUE and consequently enhancing crop yield.</p><p>A field experiment was established at the Soil and Water Management and Crop Nutrition Laboratory (SWMCNL) in Seibersdorf, Austria to determine the effect of different N fertilizers coated with N process inhibitors on maize yield in summer 2020. The field site is characterised by a moderately shallow Chernozem soil with significant gravel content. Three combinations of N fertilizer (urea or NPK) with N process inhibitors (UI and/or NI)) were tested and compared with a control treatment (without N fertilizer) and a urea application without any inhibitor. All treatments received 60 kg ha<sup>-1</sup> P<sub>2</sub>O<sub>5</sub> and 146 kg ha<sup>-1</sup> K<sub>2</sub>O. The amount of N added to each treatment receiving N fertilizer was 120 kg N ha<sup>-1</sup>. The inhibitors used were (i) UI (2-NPT: N-(2-nitrophenyl) phosphoric acid triamide), (ii) NI-1 (MPA: N-[3(5)-methyl-1H-pyrazol-1-yl) methyl] acetamide), and (iii) NI-2 (DMPP: 3,4-dimethylpyrazole phosphate). DMPP, a nitrification inhibitor, was used in combination with NPK fertilizer. A randomized complete block design with four replications was used in this study. Treatments were: T<sub>1</sub> (control treatment - without N fertilizer), T<sub>2</sub> (Urea only), T<sub>3</sub> (Urea + UI), T<sub>4</sub> (Urea + UI + NI-1), and T<sub>5 </sub>(NPK + NI-2). Urea was applied through two split applications in the T<sub>2</sub> treatment. In T<sub>3</sub>, T<sub>4</sub>, and T<sub>5</sub> treatments, N fertilizers were applied only once. Supplemental irrigation was only applied in the early stages of growth, to ensure that the crop could establish. Harvest was carried out at 98 days after planting.</p><p>The yield data showed that different fertilizer treatments had a significant (p ≤ 0.01) effect on maize yield (dry matter production). There was no significant difference between treatments 4 and 5, which had the highest yield followed by treatments 2 and 3. The comparison between T<sub>2</sub> and T<sub>3</sub> showed that the application of a urease inhibitor avoids the need for a split application of urea, which decreases labour costs. Adding NI-1 (under T<sub>4</sub>) further increases the yield. Also, the package of NPK, a common choice by farmers in Austria, in combination with the nitrification inhibitor NI-2 showed equally good results as urea combined with two inhibitors. Based on the yield results, it can be concluded that N process inhibitors play a significant role in enhancing maize yields.</p>


2015 ◽  
Vol 12 (2) ◽  
pp. 134-142
Author(s):  
MR Islam ◽  
MB Hossain ◽  
AB Siddique ◽  
MT Rahman ◽  
M Malika

An experiment was conducted at the Soil Science Field Laboratory of Bangladesh Agricultural University, Mymensingh during April to November, 2012 to study the combined effects of Sesbania green manure incorporation with different levels of nitrogen fertilizer on the growth and yield of BINA dhan7. There were five treatments for using Sesbania as pre-rice green manure (GM): Fallow (No GM), GM for incorporation at 40, 50, 60, and 70 days after sowing (DAS). T. Aman was planted after chopping the GM. For T. aman there were 9 treatments: Fallow plot received full dose (180 kg urea ha-1) of N fertilizer while plots with GM received 50 and 75% of recommended N fertilizer. The experiment was laid out in a Randomized Complete Block Design with three replications. The highest grain yield of 5752 kg ha-1 and straw yield of 6654 kg ha-1 were observed in the plot treated with 75%recommended dose of nitrogen (RDN) and green manure incorporated at 50 DAS. The lowest grain yield (4783 kg ha-1) and straw yield (5154 kg ha-1) were recorded with GM incorporated at 40 DAS + 50% RDN. The N content and uptake by the grain and straw were differed significantly due to different treatments and maximum uptake was recorded with the application of 75% recommended dose of nitrogen (RDN) and green manure incorporated at 50 DAS. The overall results indicate that application of Sesbania green manure incorporated at 50 DAS in combination with 75% recommended dose of nitrogen could be considered more effective for BINA dhan7 production DOI: http://dx.doi.org/10.3329/sja.v12i2.21925 SAARC J. Agri., 12(2): 134-142 (2014)


2018 ◽  
Vol 1 (2) ◽  
pp. 103
Author(s):  
Siti Khairani ◽  
Erwin Nyak Akoeb ◽  
Edy Sigit Sutarta ◽  
T. Sabrina

AbstractOilpalmis one of important export commodities performing as the country’s main foreign exchange from the trade of crops.Nitrogen is a limiting factor of plant growth. This study aims to determine: 1) the appropriate dose of absorption of nitrogen and growth in some high yielding varieties of oil palm; 2) the superior varieties of oil palm crops that provide no effect from the nitrogen nutrients and; 3) the interaction between varieties and nitrogen fertilizer on nitrogen nutrient absorption efficiency. This research was conducted in Palm Oil Research Centre at the District of Deli Serdang, the Province of North Sumatra.The research used Factorial Random Block Design with 2 factors. The first factor is varieties (Avros 540, PPKS 239, Simalungun, Langkat and 718PPKS). The second factor is N fertilizer which consists of without N fertilizer, 25% fertilizer recommendation, 50% fertilizer recommendation, 75% fertilizer recommendation and 100% fertilizer recommendation. The results showed that the varieties of oil palm used have different characteristics on plant height, stem diameter and number of leaves. The Simalungun variety was the best variety and its combination with 100% recommendation N was the best result in increasing plant heightof oil palm. Meanwhile the combination with 50% recommendation N was the best result in increasing stem diameter and number of leavesof oil palm.Keywords: oilpalm, nitrogen fertilizer, variety


Author(s):  
Numan Kılıçalp ◽  
Mustafa Avcı ◽  
Hatice Hızlı ◽  
Rüştü Hatipoğlu ◽  
Tugay Ayaşan

This study was conducted to determine the effects of different nitrogen (N) fertilizer levels on botanical composition, dry matter (DM) yield, chemical composition, in situ ruminal DM and NDF degradability and net energy lactation (NEL) of a native legume-grass mixture pasture. Field and degradability trials were arranged in a Complete Randomized Block Design with three replicates. Pasture was fertilized at six levels of N fertilizer (ammonium nitrate, N0, N50, N100, N150, N200 and N250 kg/ha). Three rumen cannulated Holstein Friesian heifers (3-4 year old) were used. Feed samples were incubated for 0, 8, 12, 24, 36, 48, 72 and 96 h. Application of nitrogen fertilizer results indicated that nitrogen fertilizer decreased the legumes ratio (LR) of pasture, approximately 22.4%, Although N fertilizer increased the grass ratio (GR) of pasture approximately 55.8%. Dry matter (DM), Net energy lactation (NEL, Mcal/kg) and ash contents of pasture were increased by increasing N fertilizer level. However, when N fertilizer level increased acid detergent fiber (ADF) concentration of pasture decreased. Application of the different rate of nitrogen fertilizer had no effect on in situ rumen degradability of DM and NDF of pasture. It was also found that there was the significant positive relationship between effective NDF degradability at 48 h. rumen incubation period and different level of N fertilizer. In addition, it was determined that there was a linear and quadratic positive relationship between DM yield and different nitrogen doses. In conclusion, different rates of nitrogen application changed botanical composition, decreased ADF content and increased NEL and effective rumen degradability of neutral detergent fiber (EDNDF 48 h.) of pasture.


Author(s):  
Nikolina CHEIMONA ◽  
Charis Konstantina KONTOPOULOU ◽  
Anastasia PAPANDREOU ◽  
Ioanna TABAXI ◽  
Ilias TRAVLOS ◽  
...  

From May to September 2016, a corn hybrid was sown in a field in central Greece. The experiment was laid out in a randomized complete block design with six replications and five fertilization treatments, namely NutriSphere-N Nitrogen Fertilizer (75%), NutriSphere-N Nitrogen Fertilizer (100%), AVAIL Phosphorus Fertilizer (75%), AVAIL Phosphorus Fertilizer (100%) and unfertilized (control). Data analysis confirmed that the different type of fertilization has a significant effect on the composition of weed flora. In particular, the results of the present study indicated significant differences between the fertilization treatments concerning density and diversity of weeds. Furthermore, weed diversity in the control treatment was highest, while it was lower in plots receiving application of N and P. However, total weed dry mass was lower in plots receiving no fertilizer and P fertilization, and highest in plots receiving N. Differences in terms of weed growth between the two types of fertilization could be attributed to differences revealed in the composition of the weed flora. 


2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Gribaldi Gribaldi ◽  
Nurlaili Nurlaili ◽  
Nurmala Dewi ◽  
Ekawati Danial ◽  
Firnawati Sakalena ◽  
...  

This research was conducted from July to October 2015, using Randomized Block Design with two treatment factors and three replications for each treatment. The first factor was rice varieties (V): V1 = IR 64; V2 = Inpara 5. The second factor was fertilizer (N): N0: without submergence, all N fertilizer was given during planting; N1: all N fertilizer dose was given during planting; and N2: 1/2 dose of N fertilizer was given during planting; the rest was given at 42 days after planting. The submergence was during 7–14 days after planting; N3 = the entire dose of N fertilizer that was given during planting, N4 = 1/2 the dose of N fertilizer that was given during planting, and the rest was given at 42 days after planting. The submergence was during 7–14 and 28–35 days after planting. The results showed that the management of nitrogen fertilizer application had effect on rice growth and production which experienced dirty water submergence stress; the application of 1/2 dose of N fertilizer given during planting had the best effect on rice growth and production; the longer the submergence period for rice variety, the higher the effect on rice growth and production.


Author(s):  
J.N. Abedalrahman ◽  
R.J. Mansor ◽  
D.R. Abass

A field experiment was carried out in the field of the College of Agriculture / University of Wasit, located on longitude  45o   50o   33.5o   East and latitude 32o 29o 49.8o North, in Spring season of the agricultural season 2019, in order to estimate the water consumption of potato crop using SWRT technology and under the drip irrigation system. The experiment was designed according to Randomized Complete Block Design (RCBD) with three replications and four treatments that include of the SWRT treatment (the use of plastic films under the plant root area in an engineering style), and the treatment of vegetal fertilizer (using Petmos), organic fertilizer (sheep manure), and the control treatment . Potato tubers (Solanum tuberosum L.)  var. Burin was planted for spring season on 10/2/2019 at the soil depth of 5-10 cm. The highest reference water consumption for the potato crop during the season was calculated by Najeeb Kharufa, which was 663.03 mm. The highest actual water consumption for the potato crop during the season for the control treatment was 410.1 mm. The results showed increase in the values of the crop coefficient (Kc) in the stages of tubers formation and tubers filling stage as compared to the vegetative and ripening stages, ranged from 1.37-1.92 for the two stages of tubers formation and tubers filling. The SWRT treatment gave the highest water use efficiency during the season, was 3.46 kg m-3 .


Author(s):  
Hayyawi W.A. Al-juthery ◽  
Estabraq Hilal Obaid Al-Maamouri

Investigating the effect of urea and nano-nitrogen fertigation and foliar application of nano B and Mo on growth and yield of potato Solanum tuberosum L. [Rivera-A]. The study was conducted in a private farm located in the Al-Taleah area - Babylon governorate. The experiment consisted of (12) treatments consisting of separated fertigation of nano nitrogen (25% N) and urea (46% N), single treatments of leaf spraying of nano Mo (5%), Nano B (9%), nano-binary combinations (Mo+B) and (U+ Nano Mo), (U+Nano B), Nano (N+Mo), Nano (N+B), and tricombination treatments of (U+Mo+B), Nano (N+Mo+B) additional to the control treatment. Randomize Complete Block Design (RCBD) and one way simple experiment with three replicates. Fertilizers were applied at levels of 40 liters h-1 of Nano-N fertilizer (25% N) and 300 kg h-1 urea fertilizer (46% N). They were sprayed early in the morning after (40) days after planting four times. Two weeks is the period between an application and another according to the recommendation of (1) kg  h-1 nano-fertilizer of (B) and (500) g h-1 of  Mo. Fertilizers were injected and sprayed at (10, 20, 30 and 40)% of the total amount of the fertilizer were applied as the first, second, third and fourth applications, respectively. Some growth traits were tested including the chlorophyll content in the leaves, the total dry vegetative yild, the soft tubers yield, and the biological yield, proteins and ascorbic acid yield compared to the control (spray water only). The results of the Duncan test showed a significant increase in most of the studied traits of nano-tricombination (N+Mo+B) in the fresh tubers yield,  dry vegetative yield  , the biological yield, starch yield ,the total protein and ascorbic yield (37.53, 1.799, 8.138,4.152 , 481.3and 653.8 meg ha-1) respectively .compare to control (21.58 , 0.890, 4.463  ,2.323 , 366.1 and 215.5 meg ha-1) respectively.


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