Estimating Crop Nutritional Status Using Smart Apps to Support Nitrogen Fertilization. A Case Study on Paddy Rice

Accurate nitrogen (N) management is crucial for the economic and environmental sustainability of cropping systems. Different methods have been developed to increase the efficiency of N fertilizations. However, their costs and/or low usability have often prevented their adoption in operational contexts. We developed a diagnostic system to support topdressing N fertilization based on the use of smart apps to derive a N nutritional index (NNI; actual/critical plant N content). The system was tested on paddy rice via dedicated field experiments, where the smart apps PocketLAI and PocketN were used to estimate, respectively, critical (from leaf area index) and actual plant N content. Results highlighted the system’s capability to correctly detect the conditions of N stress (NNI < 1) and N surplus (NNI > 1), thereby effectively supporting topdressing fertilizations. A resource-efficient methodology to derive PocketN calibration curves for different varieties—needed to extend the system to new contexts—was also developed and successfully evaluated on 43 widely grown European varieties. The widespread availability of smartphones and the possibility to integrate NNI and remote sensing technologies to derive variable rate fertilization maps generate new opportunities for supporting N management under real farming conditions.

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Variability for Nitrogen Management in Genetically-Distant Maize (Zea mays L.) Lines: Impact of Post-Silking Nitrogen Limiting Conditions

Agronomy ◽

10.3390/agronomy8120309 ◽

2018 ◽

Vol 8 (12) ◽

pp. 309 ◽

Cited By ~ 1

Author(s):

Isabelle Quilleré ◽

Céline Dargel-Graffin ◽

Peter J. Lea ◽

Bertrand Hirel

Keyword(s):

N Uptake ◽

Predictive Marker ◽

N Fertilization ◽

High Yield ◽

N Content ◽

Whole Plant ◽

Large Level ◽

N Remobilization ◽

N Management ◽

The Impact

The impact of nitrogen (N)-limiting conditions after silking on kernel yield (KY)-related traits and whole plant N management was investigated using fifteen maize lines representative of plant genetic diversity in Europe and America. A large level of genetic variability of these traits was observed in the different lines when post-silking fertilization of N was strongly reduced. Under such N-fertilization conditions, four different groups of lines were identified on the basis of KY and kernel N content. Although the pattern of N management, including N uptake and N use was variable in the four groups of lines, a number of them were able to maintain both a high yield and a high kernel N content by increasing shoot N remobilization. No obvious relationship between the genetic background of the lines and their mode of N management was found. When N was limiting after silking, N remobilization appeared to be a good predictive marker for identifying maize lines that were able to maintain a high yield and a high kernel N content irrespective of their female flowering date. The use of N remobilization as a trait to select maize genotypes adapted to low N input is discussed.

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The early prognosis of tuber yield based on nitrogen status in potato tops

Plant Soil and Environment ◽

10.17221/388/2018-pse ◽

2018 ◽

Vol 64 (No. 11) ◽

pp. 539-545 ◽

Cited By ~ 1

Author(s):

Witold Grzebisz ◽

Jarosław Potarzycki ◽

Maria Biber

Keyword(s):

Field Experiments ◽

Tuber Yield ◽

Zinc Content ◽

Water Shortage ◽

Tuber Initiation ◽

Optimal Range ◽

N Content ◽

Phosphorus And Potassium ◽

June July ◽

N Management

The pattern of nitrogen net change (ΔN) in potato tops during the period extending from BBCH 33 to BBCH 40 is crucial for tuber yield (TY). This hypothesis was verified based on data from field experiments (2006–2008) with sequentially added nutrients (0, NP, NPK, NPKS, NPKSMg) to potato. The water shortage in June/July 2006 and in June 2008 significantly affected N content, and in turn TY. The TY was reduced by 38% in 2006 and by 23% in 2008, as compared to 2007 (53.7 t/ha). The N content in potato tops at BBCH 40 of 2.5% indicated the lowest TY, whereas 4.3% the maximum TY. The ΔN of +0.4% within the period from BBCH 33 to BBCH 40 determined the optimal range of the N content for the maximum TY (3.9–4.3%). The ΔN trend depended on the change of phosphorus and potassium contents. The key reason of N inefficiency was the shortage of potassium (K), resulting in its negligible change within this period. The pattern of zinc content at BBCH 40 reflected fairly well disturbances in N as well as K supply to potato. A good supply of K and Zn to potato can improve N management just before tuber initiation.

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Nitrogen and green foxtail (Setaria viridis) competition effects on corn growth and development

Weed Science ◽

10.1614/ws-03-071r1 ◽

2004 ◽

Vol 52 (6) ◽

pp. 1039-1049 ◽

Cited By ~ 19

Author(s):

R. Jason Cathcart ◽

Clarence J. Swanton

Keyword(s):

Organic Matter ◽

Plant Height ◽

Growth And Development ◽

Field Experiments ◽

Kernel Weight ◽

N Fertilizer ◽

Additional Stress ◽

N Content ◽

Area Index ◽

Green Foxtail

Agronomic research on the effects of nitrogen fertilizer and weed control in corn has focused primarily on maintaining or increasing yield. Few studies have examined the effect of nitrogen (N) fertilizer rate or weed competition (or both) on whole plant growth and development. The objectives of this research were to determine how N influences the growth and development of corn and to explore how green foxtail density affects this relationship. Field experiments were conducted on a sandy low organic matter soil from 1999 to 2001. The experiment was designed as a factorial with N rate ranging from 0 to 200 kg N ha−1and targeted green foxtail density ranging from 0 to 300 plants m−2. Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight. However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level. Despite having significant main effects, there was no interaction between N rate and green foxtail density. Results indicate that in corn grown on a coarse-textured soil with low organic matter, the additional stress brought about by the presence of green foxtail exacerbated the effect of low N rates on corn growth and development. More intensive weed management may be required in corn if N fertilizer rates are reduced.

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Influence of Nitrogen on Growth Performance of Hybrid and Inbred Rice (Oryza sativa L.) Varieties in Boro Season

The Agriculturists ◽

10.3329/agric.v5i1.5201 ◽

2010 ◽

pp. 77-85

Author(s):

MS Islam ◽

MSU Bhuiya

Keyword(s):

Plant Height ◽

Field Experiments ◽

Silty Clay ◽

Higher Plant ◽

N Application ◽

Area Index ◽

Crop Growth Rate ◽

Hybrid Variety ◽

Loam Soil ◽

N Management

Field experiments were conducted during boro season of 2002 and 2003 at the Bangladesh Rice Research Institute (BRRI) farm having silty clay loam soil. Hybrid variety Sonarbangla-1 and BRRI hybrid dhan1 and modern inbred variety BRRI dhan29 were used in the experiments. Zero to 160 kg N ha-1 with 40 kg interval and different application schedules, chlorophyll meter based (SPAD35) N application and urea supper granules (USG) @ 80 kg N ha-1 were used as N treatments. During boro 2002, BRRI hybrid dhan1 had 10-15% higher tiller number, leaf area index (LAI) and crop growth rate (CGR) than Sonarbangla-1 and BRRI dhan29. Among the N managements, N9 (USG), N5 (160 kg N ha-1 with basal), N6 (160 kg N ha-1 without basal), and N7 (SPAD based N application with basal) showed 10-15% higher plant height, tiller hill-1, LAI and CGR. During boro 2003, Sonarbangla-1 and BRRI hybrid dhan1 had 10-15% higher plant height, tiller hill-1, LAI and CGR compared to the BRRI dhan29. Among the N management, N9 (USG), N5, N6, N7, N3 (120 kg N ha-1 with basal) and N4 (120 kg N ha-1 without basal) treated plots performed better in terms of growth. The LAI and CGR were reduced by 20-25 % at 60 DAT during 2003 compared to 2002 due to cold and the growth of BRRI dhan29 was restricted much.

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Nitrate-N in the Soil Profiles of Long-term Field Experiments

Agrokémia és Talajtan ◽

10.1556/agrokem.51.2002.1-2.17 ◽

2002 ◽

Vol 51 (1-2) ◽

pp. 139-146 ◽

Cited By ~ 1

Author(s):

É. Bircsák ◽

Tamás Németh

Keyword(s):

Crop Production ◽

Field Experiments ◽

N Fertilization ◽

Point Of View ◽

Soil Profiles ◽

Mineral N ◽

N Content ◽

Farm Scale ◽

Additional Costs

Long-term N fertilization experiments were established with identical treatments at two different growing areas in Hungary: one on a calcareous sandy soil (Őrbottyán) and the other on a calcareous chernozem soil (Nagyhörcsök). The aim was to create differences in mineral-N content in the soil profiles in order to determine their N supplying capacity and to establish whether the accumulated nitrate may be regarded as a supply index for crop production. The results showed that under certain environmental conditions N may accumulate in the soil profile in the form of nitrate, resulting from N fertilization in previous years, to such an extent that it must be taken into consideration when determining the fertilizer rates to be applied. This is important not only from the point of view of economical management and environment protection, but also for reaching better yield quality. The calculations can be reliably performed if they are based on the measurement and calibration of the soil's mineral-N content. The environmental importance of such calibration experiments is that by estimating the utilization of N from the mineral-N pool, the additional costs incurred due to over-fertilization can be eliminated, and at the same time the potential danger of NO 3 leaching to the groundwater can be reduced. Extrapolation of the experimental results to farm scale can lead to both economical and environmental achievements.

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GROWTH AND YIELD OF COMMON BEAN AS AFFECTED BY SEED INOCULATION WITH RHIZOBIUM AND NITROGEN FERTILIZATION

Experimental Agriculture ◽

10.1017/s001447971600065x ◽

2016 ◽

Vol 54 (1) ◽

pp. 16-30 ◽

Cited By ~ 2

Author(s):

RODRIGO LUIZ NEVES BARROS ◽

LEANDRO BARBOSA DE OLIVEIRA ◽

WELLITON BARROS DE MAGALHÃES ◽

CARLOS PIMENTEL

Keyword(s):

Field Experiments ◽

Low Cost ◽

N Fertilization ◽

Additional Treatment ◽

Growth And Yield ◽

High Yield ◽

Growth Stages ◽

Rhizobium Tropici ◽

Area Index ◽

Net Assimilation

SUMMARYTwo field experiments were conducted during the rainy seasons of 2013 and 2014 to evaluate the effects of biological nitrogen fixation (BNF) and/or sowing N fertilization on the growth and yield of Phaseolus vulgaris L. In addition, leaf soluble protein content (LSPC) was measured at four growth stages in both seasons. Plants were subjected to the following treatments: only fertilized with 20 kg N ha−1 at sowing and with 40 kg N ha−1 at 25 days after emergence (DAE) (F); only inoculated with Rhizobium tropici strain SEMIA 4080 at sowing and fertilized with 40 kg N ha−1 at 25 DAE (I+N); and inoculated and fertilized with 20 kg N ha−1 at sowing and with 40 kg N ha−1 at 25 DAE (IF). An additional treatment was done only in the second season and plants were inoculated with no N fertilization at any phase (I−N). Crop growth rate and leaf area index were enhanced by IF and F treatments as compared to I+N treatment, however, net assimilation rate did not differ among the treatments. At the pollination and flowering stages for seasons, LSPC was significantly increased by IF treatment, which also caused the highest final yield compared with the remaining treatments in both seasons. Therefore, the fertilization with 20 kg N ha−1 at sowing together with inoculation and 40 kg N ha−1 at 25 DAE is recommended for obtaining high yield in bean cultivation with high technology. As the inoculation with Rhizobium at sowing and fertilization with 40 kg N ha−1 at 25 DAE (I+N) had the same crop yield as plants fertilized at sowing and at 25 DAE (F), it can be recommended for a low-cost technology cultivation employed by small farmers.

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Yield Response, Quality Traits, and Nitrogen-Use Efficiency of a Burley Tobacco Crop Grown in Mediterranean Areas (Southern Italy) as Affected by Intensive N Management

Agronomy ◽

10.3390/agronomy11091837 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1837

Author(s):

Maria Isabella Sifola ◽

Ida Di Mola ◽

Eugenio Cozzolino ◽

Lucia Ottaiano ◽

Gennaro Piccirillo ◽

...

Keyword(s):

Field Experiments ◽

Southern Italy ◽

N Uptake ◽

N Fertilization ◽

Yield Response ◽

Total N ◽

Campania Region ◽

Burley Tobacco ◽

Yield And Quality ◽

N Management

Tobacco is an annual cash crop widely cultivated over the world, which generally needs great amounts (N) of nitrogen to achieve the best yield and quality. However, with a view to sustainable and environmentally friendly agriculture, also for this crop, the reduction in N fertilization is a priority, but without negatively affecting the yield and quality of the cured product. Therefore, field experiments were conducted during 2002 and 2003 on light air-cured (Burley) tobacco at three different locations of the Campania region (Southern Italy) where high-quality light air-cured (Burley) tobacco is traditionally cultivated. At each location, the following six N fertilization treatments were compared with four replications (blocks): (i) a not fertilized control (N0); (ii) 50 kg N ha−1 (N50); 90 kg N ha−1 (N90); 130 kg N ha−1 (N130); 170 kg N ha−1 (N170); 210 kg N ha−1 (N210). The yield of cured leaves appeared positively influenced by N fertilization but not at a rate higher than 170 kg ha−1. N fertilization directly influenced nitrates and the total N content of cured leaves at all locations. The greater values of both parameters were reached at N130 or N90, respectively, at Vitulazio (CE), N170 at Bellizzi (SA), and N90 at San Giorgio del Sannio (BN). The fire holding capacity increased with N fertilization up to N170 treatment (12–13 s at CE and BN but just 8 s at SA). L* (brightness) decreased with increasing N fertilization giving cured leaves less bright and opaquer. The a/b ratio (a*, green/red; b*, blue/yellow) increased with N treatments producing cured leaves of dark hazelnut. The best scores were assigned to cured products obtained by plants fertilized with 170 kg N ha−1. N-use efficiencies were negatively influenced by N fertilization. The best NUE and N-uptake efficiency was recorded in 2002 at Vitulazio (CE), in spite of a higher NO3-N before N fertilization than other locations.

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Rotational Cropping Sequence Affects Nitrogen Fertilizer Requirements in Processing Pumpkins (Cucurbita moschata)

HortScience ◽

10.21273/hortsci.39.1.75 ◽

2004 ◽

Vol 39 (1) ◽

pp. 75-79

Author(s):

John M. Swiader ◽

William H. Shoemaker

Keyword(s):

Field Experiments ◽

Cropping Systems ◽

N Fertilization ◽

Fruit Weight ◽

N Fertilizer ◽

Yield Response ◽

Cucurbita Moschata ◽

Ripe Fruit ◽

Fertilizer Rate ◽

N Fertilizer Rate

Field experiments were conducted over a 5-year period (1994-98) to determine the effect of various cropping systems (rotations) on fertilizer N requirements in processing pumpkins [Cucurbita moschata (Duchesne ex Lam.) Duchesne ex Poir.] on medium- to fine-textured soil. Treatments consisted of a factorial combination of five N fertilization rates (0, 56, 112, 168, 224 kg·ha-1 N) and four pumpkin cropping systems: 1) pumpkins following corn (Zea mays L.); 2) pumpkins following soybeans [Glycine max (L.) Merrill]; 3) pumpkins following 2-years corn; and 4) pumpkins following fallow ground. Cropping systems were chronologically and spatially arranged in two complete cycles, with pumpkin studies taking place in 1996 and 1998. Averaged over the two studies, the optimal N fertilization rate for highest total weight of ripe fruit following soybeans was estimated at 109 kg·ha-1 N, compared to 128 kg·ha-1 N following fallow ground, even though yields were similar, suggesting a soybean N-credit of 19 kg·ha-1 N. Concurrently, the N fertilizer rate for highest total ripe fruit weight following corn was estimated at 151 kg·ha-1 N, and 178 kg·ha-1 following 2-years corn, indicating a negative rotation effect on pumpkin N requirements of 23 and 50 kg·ha-1 N, respectively. Minimum N fertilizer requirements, the N fertilizer rate associated with a ripe fruit yield of 50 t·ha-1, were calculated at 45, 37, 69, and 47 kg·ha-1 N in the respective cropping systems. Negative effects from excessive N fertilization were greater in pumpkins following soybeans than in pumpkins following corn or 2-years corn, with reductions in total ripe fruit weight of 21%, 9%, and 3%, respectively, at the highest N rate. A critical level for preplant soil NO 3-N of 17.6 mg·kg-1 was identified above which there was little or no pumpkin yield response to N fertilization.

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Response of Desert Lettuce to Controlled-release N Fertilizer

HortScience ◽

10.21273/hortsci.30.4.769f ◽

1995 ◽

Vol 30 (4) ◽

pp. 769F-769

Author(s):

C.A. Sanchez

Keyword(s):

Controlled Release ◽

Management Practices ◽

Field Experiments ◽

Management Practice ◽

Management Strategies ◽

N Fertilization ◽

N Fertilizer ◽

Marketable Yield ◽

Potential Threat ◽

N Management

Lettuce produced in the desert typically shows large yield responses to N fertilization. However, concern about the potential threat of nitrate-N to ground-water has prompted additional studies aimed at developing improved N management practices. Field experiments were conducted between 1992 and 1995 to evaluate the response of crisphead lettuce to controlled-release N fertilizer (CRN). The use of CRN was compared to a soluble N fertilizer applied preplant (PP), and a soluble N fertilizer applied in split-sidedress applications (SD). Rates of N fertilizer application ranged from 0 to 300 kg·ha–1. Lettuce generally showed significant responses to N rate and N management practice. However, response to management practice varied by site-season. When conditions for N loss were high, SD and CRN management strategies were superior. However, in other site-seasons, SD management sometimes resulted in inferior head quality and marketable yield when compared to other management strategies. Data averaged over six site-seasons shoed improved yield and quality to CRN management strategies compared to PP and SD strategies.

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Concepts and Practices for Improving Nitrogen Management for Vegetables

HortTechnology ◽

10.21273/horttech.2.1.121 ◽

1992 ◽

Vol 2 (1) ◽

pp. 121-125 ◽

Cited By ~ 9

Author(s):

George J. Hochmuth

Keyword(s):

Water Management ◽

Management Practices ◽

Management Strategies ◽

N Fertilization ◽

Nitrogen Management ◽

Land Grant ◽

Land Grant Universities ◽

Production Practices ◽

Negative Impacts ◽

N Management

Efficient N management practices usually involve many potential strategies, but always involve choosing the correct amount of N and the coupling of N management to efficient water management. Nitrogen management strategies are integral parts of improved production practices recommended by land-grant universities such as the Institute of Food and Agricultural Sciences, Univ. of Florida. This paper, which draws heavily on research and experience in Florida, outlines the concepts and technologies for managing vegetable N fertilization to minimize negative impacts on the environment.

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