scholarly journals Response to fertilizer nitrogen and water of post-rainy season sorghum on a Vertisol. 1. Biomass and light interception

1998 ◽  
Vol 131 (4) ◽  
pp. 417-428 ◽  
Author(s):  
T. J. REGO ◽  
J. L. MONTEITH ◽  
PIARA SINGH ◽  
K. K. LEE ◽  
V. NAGESWARA RAO ◽  
...  
Keyword(s):  
Rainy Season ◽  
Andhra Pradesh ◽  
Root Zone ◽  
Growth Period ◽  
Peninsular India ◽  
N Application ◽  
Radiation Coefficient ◽  
Optimum Application ◽  
Main Growth ◽  
Leaf N

In parts of peninsular India, sorghum (Sorghum bicolor L.) is grown during the dry season using water stored in the root zone. The optimum application of nitrogen is difficult to assess because no comprehensive model exists for the interaction of water and N. To explore this system as a basis for modelling in the first instance and ultimately for better management, sorghum (cv. SPH–280) was grown in the post-rainy season at ICRISAT (Andhra Pradesh, India) with and without irrigation and at six rates of nitrogen from zero to 150 kg/ha applied before sowing. The biomass of top components was measured weekly and of roots every 2 weeks. Interception of solar radiation was monitored continuously in all treatments.Leaf expansion was strongly influenced both by water and by N, whereas specific leaf area was almost independent of treatment. In the irrigated treatment, the Biomass Radiation Coefficient (e) for the main growth period was almost independent of N application at 1·3–1·4 g/MJ and was also independent of leaf N. In consequence, the main source of differences in yield was a decrease in radiation interception with decreasing N. In contrast, without irrigation, biomass, yield, e and leaf N were all maximal at 60 kg/ha N.At 33 days after emergence (DAE), root mass was almost independent of N whether water had been applied or not, but was somewhat smaller with irrigation. Later, root, leaf, and panicle mass all responded to N and to water, but stem mass was unresponsive to N with irrigation. There was evidence of translocation from stem to grain in most treatments. With irrigation, a maximum grain yield of 4·8 t/ha was obtained at 150 kg/ha N and without irrigation the maximum was 3·2 t/ha at 90 kg/ha.

Field Measurements and Simulation of Nitrogen Fate under Citrus Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498c-498
Author(s):  
A. Fares ◽  
A.K. Alva ◽  
S. Paramasivam
Keyword(s):  
Mass Balance ◽  
Best Management Practices ◽  
Rainy Season ◽  
Crop Production ◽  
Management Practices ◽  
Root Zone ◽  
Field Measurements ◽  
Irrigation Scheduling ◽  
N Leaching ◽  
Citrus Production

Water and nitrogen (N) are important inputs for most crop production. The main objectives of nitrogen best management practices (NBMP) are to improve N and water management to maximize the uptake efficiency and minimize the leaching losses. This require a complete understanding of fate of N and water mass balance within and below the root zone of the crop in question. The fate of nitrogen applied for citrus production in sandy soils (>95% sand) was simulated using a mathematical model LEACHM (Leaching Estimation And Chemistry Model). Nitrogen removal in harvested fruits and storage in the tree accounted the major portion of the applied N. Nitrogen volatilization mainly as ammonia and N leaching below the root zone were the next two major components of the N mass balance. A proper irrigation scheduling based on continuous monitoring of the soil water content in the rooting was used as a part of the NBMP. More than 50% of the total annual leached water below the root zone was predicted to occur in the the rainy season. Since this would contribute to nitrate leaching, it is recomended to avoid N application during the rainy season.

scholarly journals Combining Process Modelling and LAI Observations to Diagnose Winter Wheat Nitrogen Status and Forecast Yield

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 314
Author(s):  
Andrew Revill ◽  
Vasileios Myrgiotis ◽  
Anna Florence ◽  
Stephen Hoad ◽  
Robert Rees ◽  
...  
Keyword(s):  
Field Experiments ◽  
Process Models ◽  
Agricultural Technologies ◽  
N Application ◽  
Area Index ◽  
Complex Process ◽  
C Cycle ◽  
The Mean ◽  
Leaf N Content ◽  
Leaf N

Climate, nitrogen (N) and leaf area index (LAI) are key determinants of crop yield. N additions can enhance yield but must be managed efficiently to reduce pollution. Complex process models estimate N status by simulating soil-crop N interactions, but such models require extensive inputs that are seldom available. Through model-data fusion (MDF), we combine climate and LAI time-series with an intermediate-complexity model to infer leaf N and yield. The DALEC-Crop model was calibrated for wheat leaf N and yields across field experiments covering N applications ranging from 0 to 200 kg N ha−1 in Scotland, UK. Requiring daily meteorological inputs, this model simulates crop C cycle responses to LAI, N and climate. The model, which includes a leaf N-dilution function, was calibrated across N treatments based on LAI observations, and tested at validation plots. We showed that a single parameterization varying only in leaf N could simulate LAI development and yield across all treatments—the mean normalized root-mean-square-error (NRMSE) for yield was 10%. Leaf N was accurately retrieved by the model (NRMSE = 6%). Yield could also be reasonably estimated (NRMSE = 14%) if LAI data are available for assimilation during periods of typical N application (April and May). Our MDF approach generated robust leaf N content estimates and timely yield predictions that could complement existing agricultural technologies. Moreover, EO-derived LAI products at high spatial and temporal resolutions provides a means to apply our approach regionally. Testing yield predictions from this approach over agricultural fields is a critical next step to determine broader utility.

scholarly journals Optimizing Nitrogen Application for Growth and Productivity of Pomegranates

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 366
Author(s):  
Silit Lazare ◽  
Yang Lyu ◽  
Uri Yermiyahu ◽  
Yehuda Heler ◽  
Alon Ben-Gal ◽  
...  
Keyword(s):  
N Uptake ◽  
N Fertilization ◽  
Field Conditions ◽  
Nitrogen Application ◽  
N Application ◽  
Environmentally Responsible ◽  
Irrigation Solution ◽  
Vegetative Indices ◽  
Leaf N ◽  
Usage Efficiency

Quantification of actual plant consumption of nitrogen (N) is necessary to optimize fertilization efficiency and minimize contamination of earth resources. We examined the performance of fruit-bearing pomegranate trees grown in soilless media and exposed to eight N-fertigation treatments, from 5 to 200 mg N L−1. Reproductive and vegetative indices were found to be optimal when 20 to 70 mg N L−1 was supplied. Nitrogen application levels over 70 mg L−1 reduced pomegranate development and reproduction. N uptake in low-level treatments was almost 100% and decreased gradually, down to 13% in 200 mg N L−1 treatment. N usage efficiency was maximized under 20 mg N L−1, in which case 80% to 90% of added N was taken up by the trees. At high N application, its efficiency was reduced with less than 50% utilized by the trees. Leaf N increased to a plateau as a function of increasing irrigation solution N, maximizing at ~15 to 20 mg N g−1. Therefore, analysis of diagnostic leaves is not a valid method to identify excessive detrimental N. The results should be valuable in the development of efficient, sustainable, environmentally responsible protocols for N fertilization in commercial pomegranate orchards, following adaptation and validation to real soil field conditions.

scholarly journals Foliar analysis in experimentally grown Lacatan bananas in relation to leaf production and bunch weight.

1962 ◽  
Vol 10 (2) ◽  
pp. 118-126 ◽  
Author(s):  
W.J. Brezowsky ◽  
J. Van Biesen
Keyword(s):  
Rainy Season ◽  
Foliar Analysis ◽  
Depressing Effect ◽  
Leaf Production ◽  
Positive Effect ◽  
Leaf N

Foliar analyses from October to April (the drier part of the year) showed a positive effect of an increased potash application on leaf K, and a depressing effect on leaf Mg. Both these effects were statistically insignificant just before and during the period when most of the plants started to shoot. There was no significant effect of increased N applications on leaf N, except in the early part of the rainy season. Increased K also had a significant effect on bunch weight, hand weight and the number of hands per stem.-Cameroons Develop. Corp. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Avifaunal diversity in the scrub forest of Sri Lankamalleswara Wildlife Sanctuary, Andhra Pradesh, India

2017 ◽  
Vol 9 (9) ◽  
pp. 10679
Author(s):  
Sumant Mali ◽  
Chelmala Srinivasulu ◽  
Asad R. Rahmani
Keyword(s):  
Andhra Pradesh ◽  
Bird Species ◽  
Wildlife Sanctuary ◽  
Peninsular India ◽  
Scrub Forests ◽  
Scrub Forest

A total of 115 bird species belonging to 47 families were recorded in the scrub forests of the Sri Lankamalleswara Wildlife Sanctuary, Andhra Pradesh, India in a survey carried out from May 2014 to April 2015.  Of these, 107 species were resident and nine species were resident migrants. The scrub forests of peninsular India are equally important as other habitats for avifaunal assemblages.

Contrasting growth pattern and nitrogen economy in ancient and modern wheat varieties

2015 ◽  
Vol 95 (5) ◽  
pp. 851-860 ◽  
Author(s):  
F. Pourazari ◽  
G. Vico ◽  
P. Ehsanzadeh ◽  
M. Weih
Keyword(s):  
Resource Availability ◽  
Growth Pattern ◽  
Growth Period ◽  
Nutrient Supply ◽  
Wheat Varieties ◽  
N Content ◽  
Modern Wheat ◽  
Use Efficiency ◽  
Modern Varieties ◽  
Main Growth

Pourazari, F., Vico, G., Ehsanzadeh, P. and Weih, M. 2015. Contrasting growth pattern and nitrogen economy in ancient and modern wheat varieties. Can. J. Plant Sci. 95: 851–860. Nutrient availability, especially nitrogen (N) availability, is a limiting factor for crop production in many regions of the world. Modern crop varieties often produce high yields under high resource availability, whereas ancient varieties are expected to have characteristics more suitable under low resource availability. To test this expectation, we compared the growth and N use efficiency (NUE) of some varieties of ancient hulled wheat, Triticum turgidum spp. dicoccum, and modern free-threshing wheat, T. aestivum and T. turgidum spp. durum. The wheats were grown under different nutrient fertilization (F) levels in two contrasting environments (field in Iran and outdoor growth container in Sweden). Grain yield was significantly higher in modern varieties than in ancient varieties, regardless of fertilization level. In contrast, N uptake efficiency (i.e., mean N in the plant during the main growth period over N in the initial seed grain) and grain N concentration were generally higher in the ancient varieties. Nitrogen use efficiency, defined as the ratio of the grain N content to the sown seed N content, was higher in the ancient varieties only at lower nutrient supply, because in modern varieties higher nutrient supply resulted in a marked increase in NUE through greatly enhanced grain-specific N efficiency (grain yield per mean plant N content during the main growth period). The modern varieties also showed greater fertilization responses in above-ground biomass and leaf area than ancient varieties. The results are relevant in the context of wheat breeding for nutrient use efficiency.

Effect of tree leaf N status and N application time on yield and fruit N partitioning of mango

2017 ◽  
pp. 161-166
Author(s):  
D. Hamilton ◽  
C. Martin ◽  
M. Bennet ◽  
M. Hearnden ◽  
C.A. Asis
Keyword(s):  
Application Time ◽  
N Application ◽  
N Partitioning ◽  
Tree Leaf ◽  
N Status ◽  
Leaf N

Typification and taxonomic remarks of Indobanalia (Amaranthaceae) in India

Phytotaxa ◽  
2021 ◽  
Vol 513 (3) ◽  
pp. 265-270
Author(s):  
DUILIO IAMONICO ◽  
SINDHU ARYA ◽  
VENUGOPALAN NAIR SARADAMMA ANIL KUMAR
Keyword(s):  
Sri Lanka ◽  
Endemic Species ◽  
Tamil Nadu ◽  
Andhra Pradesh ◽  
Morphological Characterization ◽  
Herbarium Specimens ◽  
Peninsular India ◽  
Field Surveys ◽  
The Moment

Indobanalia thyrsiflora is an endemic species occurring in peninsular India (Andhra Pradesh, Karnataka, Kerala and Tamil Nadu States) and Sri Lanka. A nomenclatural study of the basionym Banalia thyrsiflora, published by Moquin-Tandon in Candolle’s Prodromus (year 1849), is carried out and the name is lectotypified on a specimen deposited at P (barcode P00609924); isolectotypes are traced at K and CAL. A preliminary morphological characterization of the species is also given, based on field surveys and examination of herbarium specimens. We noted that I. thyrsiflora is highly variable. However, we prefer to avoid, for the moment, taxonomic conclusions about the various morphotypes found, waiting the complete results of this ongoing morphological and molecular investigations.

scholarly journals Inoculation and N Fertilization Affect the Dry Matter, N Fixation, and Bioactive Compounds in Sulla Leaves

Agronomy ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 289 ◽  
Author(s):  
Leonardo Sulas ◽  
Giuseppe Campesi ◽  
Giovanna Piluzza ◽  
Giovanni A. Re ◽  
Paola A. Deligios ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Dry Matter ◽  
Seed Set ◽  
Natural Habitat ◽  
N Fertilization ◽  
N Fixation ◽  
N Application ◽  
Uninoculated Control ◽  
The Relationship ◽  
Leaf N

Sulla (Sulla coronaria [L.] Medik), a Mediterranean short-lived legume with tolerance to drought-prone environments, requires inoculation outside its natural habitat. Its leaves are appreciated for the bromatological composition and content of bioactive compounds. However, no information is available regarding the distinct effects of inoculation and nitrogen (N) applications on leaf dry matter (DM), fixed N, and bioactive compounds. Sulla leaves were sampled from the vegetative stage to seed set in Sardinia (Italy) during 2013–2014 and leaf DM, N content, and fixed N were determined. Compared to the best performing inoculated treatments, DM yield and fixed N values of the control only represented 8% to 20% and 2% to 9%, respectively. A significant relationship between fixed N and leaf DM yield was established, reaching 30 kg fixed N t–1 at seed set. Significant variations in leaf atom% 15N excess and %Ndfa quantified decreases in leaf N fixation coupled with N application. Moreover, the petiole content of phenolic compounds markedly increased in the uninoculated control, suggesting deeper investigations on the relationship between bioactive compounds and inoculation treatments. Results highlighted substantial variation in DM, N yields, N-fixation ability, and content of bioactive compounds of sulla leaves caused by inoculation and N fertilization.

scholarly journals Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Fluorescence Sensor ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Fluorescence Sensors ◽  
N Application ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Status ◽  
Leaf N

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

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