On-farm soil N supply and N nutrition in the rice–wheat system of Nepal and Bangladesh

1999 ◽  
Vol 64 (3) ◽  
pp. 273-286 ◽  
Author(s):  
C Adhikari ◽  
K.F Bronson ◽  
G.M Panuallah ◽  
A.P Regmi ◽  
P.K Saha ◽  
...  
Keyword(s):  
Soil N ◽  
N Nutrition ◽  
N Supply ◽  
On Farm

scholarly journals Enhancing Sustainable Potato Production—A Case Study in Northern China

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1322
Author(s):  
Na Wang ◽  
Pytrik Reidsma ◽  
Ziquan Wang ◽  
Xiaohan Zhou ◽  
Corné Kempenaar ◽  
...  
Keyword(s):  
Environmental Impacts ◽  
Resource Use ◽  
Northern China ◽  
Potato Production ◽  
Experimental Results ◽  
Soil N ◽  
Sustainable Practices ◽  
N Supply ◽  
Use Efficiency ◽  
On Farm

Potato is the fourth most important staple crop in China. To meet the increased demand and environmental objectives, potato production should be enhanced by sustainable practices that aim to maximize yield and resource use efficiencies and minimize environmental impacts. Most experiments so far have taken place on experimental stations, while on-farm experimentation is needed to evaluate, demonstrate and scale more sustainable practices. On-farm field experiments were conducted in two years (2017, 2018) in northern China to investigate and demonstrate the effects of different nitrogen (N) fertiliser and irrigation input levels on potato yield, quality, resource use efficiency and environmental impacts. The 2017 experimental results on one farmer’s field showed that under irrigated conditions, adding N fertiliser (from 0 to 267 kg ha−1) did not increase yield due to the high soil N supply, rather it reduced tuber quality. The 2018 experimental results, in which four additional farmers were involved, indicated that, under irrigated conditions, reducing N fertiliser from the current rates (189–252 kg ha−1) to lower levels (109–181 kg ha−1) did not affect yield nor quality; while further reducing N fertiliser inputs (to 9–117 kg ha−1) resulted in a yield reduction (18% on average) in some fields. In both years, irrigation improved tuber yield and quality compared to that under rainfed conditions. The nitrogen use efficiency was improved and N surplus was reduced by applying irrigation and reducing N fertiliser input. Farmers expressed they were willing to reduce N fertiliser input by 10–20%, and indicated that a widespread adaptation of drip irrigation is hindered by the high costs and labor requirements. Site-specific recommendations on optimum N fertiliser and irrigation management must be provided, which should preferably be based on regular quantitative monitoring of soil N supply and soil moisture content.

scholarly journals The Use of Chlorophyll Meters to Assess Crop N Status and Derivation of Sufficiency Values for Sweet Pepper

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2949 ◽  
Author(s):  
Romina de Souza ◽  
M. Teresa Peña-Fleitas ◽  
Rodney B. Thompson ◽  
Marisa Gallardo ◽  
Rafael Grasso ◽  
...  
Keyword(s):  
Experimental Work ◽  
Sweet Pepper ◽  
Commercial Production ◽  
Vegetable Crops ◽  
Phenological Stages ◽  
N Nutrition ◽  
N Supply ◽  
N Management ◽  
On Farm ◽  
N Status

Chlorophyll meters are promising tools for improving the nitrogen (N) management of vegetable crops. To facilitate on-farm use of these meters, sufficiency values that identify deficient and sufficient crop N status are required. This work evaluated the ability of three chlorophyll meters (SPAD-502, atLEAF+, and MC-100) to assess crop N status in sweet pepper. It also determined sufficiency values for optimal N nutrition for each meter for pepper. The experimental work was conducted in a greenhouse, in Almería, Spain, very similar to those used for commercial production, in three different crops grown with fertigation. In each crop, there were five treatments of different N concentration in the nutrient solution, applied in each irrigation, ranging from a very deficient to very excessive N supply. In general, chlorophyll meter measurements were strongly related to crop N status in all phenological stages of the three crops, indicating that these measurements are good indicators of the crop N status of pepper. Sufficiency values determined for each meter for the four major phenological stages were consistent between the three crops. This demonstrated the potential for using these meters with sufficiency values to improve the N management of commercial sweet pepper crops.

Legume–barley intercropping stimulates soil N supply and crop yield in the succeeding durum wheat in a rotation under rainfed conditions

2015 ◽  
Vol 89 ◽  
pp. 150-161 ◽  
Author(s):  
Antonella Scalise ◽  
Demetrio Tortorella ◽  
Aurelio Pristeri ◽  
Beatrix Petrovičová ◽  
Antonio Gelsomino ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Crop Yield ◽  
Soil N ◽  
N Supply ◽  
Rainfed Conditions

Leaf and stem structure of poplar (Populus ×euramericana) as Influenced by O3, NO2, their combination, and different soil N supplies

1996 ◽  
Vol 26 (4) ◽  
pp. 649-657 ◽  
Author(s):  
M.S. Günthardt-Goerg ◽  
P. Schmutz ◽  
R. Matyssek ◽  
J.B. Bucher
Keyword(s):  
Stomatal Density ◽  
Dry Weight ◽  
Soil N ◽  
Protein Patterns ◽  
Mesophyll Cells ◽  
Leaf Injury ◽  
Populus Euramericana ◽  
N Supply ◽  
High Soil ◽  
Leaf Dry Weight

Although increasing tropospheric ozone (O3) concentrations as well as precursor NO2 emissions and N deposition have been observed, the combination of their effects on deciduous trees is little understood. We therefore examined the growth and leaf injury response of a model tree (Populus ×euramericana (Dode) Guinier cuttings exposed before flush and until they reached a height of more than 1 m) to low and high soil N supply (105 or 315 mg N•L−1 substrate volume), to filtered air, and to filtered air with NO2 (sinusoidal daily course with a mean of 100 nL•L−1), with O3 (60 nL•L−1), or with a combination of both in climate-controlled chambers. High soil N increased total plant dry weight, leaf area, and xylem radius in plants fumigated with or without added NO2 or O3. The number of leaves increased with high soil N independent of added NO2. The stomatal density was influenced by soil N and by fumigations, but the appearance of leaf injury symptoms, leaf loss, specific leaf weight, and bark radius were not modified by the soil N regimes. NO2 alone, though applied in a sixfold ambient concentration, did not significantly increase plant growth. NO2 and O3 alone had opposite effects on specific leaf dry weight, stomatal density, and in the high fertilization regime, on the bark radius. The decrease in specific leaf dry weight and the appearance of early leaf symptoms were enhanced by NO2 added to O3. Visible leaf injury caused by O3 increased in parallel with microscopic changes in mesophyll cell walls, in the starch and protein patterns of mesophyll cells, in the bark cell content, and in the phloem sieve pores. NO2 enhanced the negative effect of O3 rather than compensated for a low soil N supply.

scholarly journals Nitrogen Supply Influences Carbohydrate Partitioning of Pepper Seedlings and Transplant Development

1991 ◽  
Vol 116 (6) ◽  
pp. 995-999 ◽  
Author(s):  
Beny Aloni ◽  
Tamara Pashkar ◽  
Lea Karni ◽  
Jaleh Daie
Keyword(s):  
Soluble Sugar ◽  
Leaf Age ◽  
Carbohydrate Partitioning ◽  
N Nutrition ◽  
Post Transplant ◽  
Nitrogen Levels ◽  
Unit Leaf ◽  
Leaf Chlorophyll ◽  
N Supply ◽  
Root Shoot Ratio

We investigated the effects of N nutrition on growth and carbohydrate partitioning of pepper (Capsicum annuum L., cv. Maor) seedlings in the greenhouse and on their subsequent recovery and development after transplanting. Seedlings received 0, 30, 100, or 200 mg N/liter for 14 days, after which they were transplanted and received 100 mg N/liter. Nitrogen levels below 100 mg·liter−1 inhibited shoot growth and leaf chlorophyll content; both were severely inhibited in the absence of supplemental N. Root growth had a negative relation with N supply; an enhanced root: shoot ratio was observed under low-N regimes. On a unit-leaf-area basis, CO2 fixation was not affected when N was present; however, it was greatly inhibited in the absence of N. Changes in the leaf starch and soluble sugar concentrations occurred as a function of N supply and leaf age. In the roots, low N led to lower sucrose and higher levels of hexose and starch. More sucrose was transported and accumulated into leaf veins of low-N tissue. Exogenously supplied 14C-labeled sucrose was rapidly converted into starch in the low-N tissue. Seedlings that received 100 mg N/liter had the highest post-transplant growth rate and flowered earlier. Carbohydrate status of young pepper seedlings influenced their post-transplant recovery. Optimal N supply is essential for full recovery and development of transplants.

Impact of irrigation management on paddy soil N supply and depth distribution of abiotic drivers

2018 ◽  
Vol 261 ◽  
pp. 12-24 ◽  
Author(s):  
Masuda Akter ◽  
Heleen Deroo ◽  
Ahammad Mostafa Kamal ◽  
Mohammed Abdul Kader ◽  
Elizabeth Verhoeven ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Depth Distribution ◽  
Irrigation Management ◽  
Soil N ◽  
N Supply

Validation of NBudget for estimating soil N supply in Australia's northern grains region in the absence of soil test data

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 590 ◽  
Author(s):  
David F. Herridge
Keyword(s):  
Soil Water ◽  
Organic N ◽  
Soil N ◽  
Limited Information ◽  
Available N ◽  
Support Tool ◽  
Grain Yields ◽  
N Supply ◽  
Nitrate N ◽  
Winter Crop

Effective management of fertiliser nitrogen (N) inputs by farmers will generally have beneficial productivity, economic and environmental consequences. The reality is that farmers may be unsure of plant-available N levels in cropping soils at sowing and make decisions about how much fertiliser N to apply with limited information about existing soil N supply. NBudget is a Microsoft (Armonk, NY, USA) Excel-based decision support tool developed primarily to assist farmers and/or advisors in Australia’s northern grains region manage N. NBudget estimates plant-available (nitrate) N at sowing; it also estimates sowing soil water, grain yields, fertiliser N requirements for cereals and oilseed crops and N2 fixation by legumes. NBudget does not rely on soil testing for nitrate-N, organic carbon or soil water content. Rather, the tool relies on precrop (fallow) rainfall data plus basic descriptions of soil texture and fertility, tillage practice and information about paddock use in the previous 2 years. Use is made of rule-of-thumb values and stand-alone or linked algorithms describing, among other things, rates of mineralisation of background soil organic N and fresh residue N. Winter and summer versions of NBudget cover the 10 major crops of the region: bread wheat, durum, barley, canola, chickpea and faba bean in the winter crop version; sorghum, sunflower, soybean and mung bean in the summer crop version. Validating the winter crop version of NBudget estimates of sowing soil nitrate-N against three independent datasets (n=65) indicated generally close agreement between measured and predicted values (y=0.91x+16.8; r2=0.78). A limitation of the tool is that it does not account for losses of N from waterlogged or flooded soils. Although NBudget also predicts grain yields and fertiliser N requirements for the coming season, potential users may simply factor predicted soil N supply into their fertiliser decisions, rather than rely on the output of the tool. Decisions about fertiliser N inputs are often complex and are based on several criteria, including attitudes to risk, history of fertiliser use and costs. The usefulness and likely longevity of NBudget would be enhanced by transforming the current Excel-based tool, currently available on request from the author, to a stand-alone app or web-based tool.

scholarly journals Nitrogen Nutrition of European Beech Is Maintained at Sufficient Water Supply in Mixed Beech-Fir Stands

Forests ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 733 ◽  
Author(s):  
Ruth-Kristina Magh ◽  
Fengli Yang ◽  
Stephanie Rehschuh ◽  
Martin Burger ◽  
Michael Dannenmann ◽  
...  
Keyword(s):  
Water Supply ◽  
Water Relations ◽  
European Beech ◽  
Soil Parameters ◽  
Silver Fir ◽  
Soil N ◽  
Uptake Capacity ◽  
Mixed Stands ◽  
Total N ◽  
N Nutrition

Research highlights: Interaction effects of coniferous on deciduous species have been investigated before the background of climate change. Background and objectives: The cultivation of European beech (Fagus sylvatica L.) in mixed stands has currently received attention, since the future performance of beech in mid-European forest monocultures in a changing climate is under debate. We investigated water relations and nitrogen (N) nutrition of beech in monocultures and mixed with silver-fir (Abies alba Mill.) in the Black Forest at different environmental conditions, and in the Croatian Velebit at the southern distribution limit of beech, over a seasonal course at sufficient water availability. Material and methods: Water relations were analyzed via δ13C signatures, as integrative measures of water supply assuming that photosynthesis processes were not impaired. N nutrition was characterized by N partitioning between soluble N fractions and structural N. Results: In the relatively wet year 2016, water relations of beech leaves, fir needles and roots differed by season, but generally not between beech monocultures and mixed cultivation. At all sites, previous and current year fir needles revealed significantly lower total N contents over the entire season than beech leaves. Fir fine roots exhibited higher or similar amounts of total N compared to needles. Correlation analysis revealed a strong relationship of leaf and root δ13C signatures with soil parameters at the mixed beech stands, but not at pure beech stands. While glutamine (Gln) uptake capacity of beech roots was strongly related to soil N in the monoculture beech stands, arginine (Arg) uptake capacities of beech roots were strongly related to soil N in mixed stands. Conclusions: Leaf N contents indicated a facilitative effect of silver-fir on beech on sites where soil total N concentrations where low, but an indication of competition effect where it was high. This improvement could be partially attributed to protein contents, but not to differences in uptake capacity of an individual N source. From these results it is concluded that despite similar performance of beech trees at the three field sites investigated, the association with silver-fir mediated interactive effects between species association, climate and soil parameters even at sufficient water supply.

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