Strategies for variable rate nitrogen fertilization in hummocky terrain

1997 ◽  
Vol 77 (4) ◽  
pp. 589-595 ◽  
Author(s):  
H. J. Beckie ◽  
A. P. Moulin ◽  
D. J. Pennock
Keyword(s):  
Triticum Aestivum ◽  
Precision Agriculture ◽  
Linum Usitatissimum ◽  
Black Soil ◽  
Variable Rate ◽  
Fertilizer N ◽  
Management Zones ◽  
Fertilizer Use ◽  
Net Returns ◽  
Use Efficiency

A study was conducted from 1994 to 1996 in a hummocky landscape near Prince Albert, Saskatchewan in the moist Black soil climatic zone to determine the best criterion for defining fertilizer management zones within a field and how much fertilizer to apply in each zone. A uniform rate fertilization (CF) treatment was compared with three variable rate fertilization (VRF) treatments that used management zones based on soil residual nitrate-N (VRFrn), organic carbon (VRFom) and topography (VRFt). For VRFom and VRFt, fertilizer recommendations were based on soil residual N levels within zones and yield potentials that differed between zones. Flax (Linum usitatissimum) was grown in 1994, spring wheat (Triticum aestivum) in 1995, and canola (Brassica rapa) in 1996. Fertilizer use efficiency (FUE), defined as kilograms seed per kilogram fertilizer N, was markedly higher for VRFom and VRFt than CF or VRFrn. This enhanced FUE resulted in net returns, defined as crop revenue minus fertilizer cost, of about $10 ha−1 more than that of CF. Three successive years of VRF in this study suggests that this practice can enhance the efficient use of fertilizer N and has potential to increase profitability of fertilizer use, by more closely matching fertilizer N inputs with crop nutrient requirements. Key words:Brassica rapa, Linum usitatissimum, Triticum aestivum, nitrogen, variable rate fertilization, precision agriculture

scholarly journals Simplified and Hybrid Remote Sensing-Based Delineation of Management Zones for Nitrogen Variable Rate Application in Wheat

Agriculture ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1104
Author(s):  
Mohammad Rokhafrouz ◽  
Hooman Latifi ◽  
Ali A. Abkar ◽  
Tomasz Wojciechowski ◽  
Mirosław Czechlowski ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Precision Agriculture ◽  
Statistical Tests ◽  
Unsupervised Clustering ◽  
Data Availability ◽  
Agricultural Drought ◽  
Rank Test ◽  
Variable Rate ◽  
Management Zones ◽  
Variable Rate Application

Enhancing digital and precision agriculture is currently inevitable to overcome the economic and environmental challenges of the agriculture in the 21st century. The purpose of this study was to generate and compare management zones (MZ) based on the Sentinel-2 satellite data for variable rate application of mineral nitrogen in wheat production, calculated using different remote sensing (RS)-based models under varied soil, yield and crop data availability. Three models were applied, including (1) a modified “RS- and threshold-based clustering”, (2) a “hybrid-based, unsupervised clustering”, in which data from different sources were combined for MZ delineation, and (3) a “RS-based, unsupervised clustering”. Various data processing methods including machine learning were used in the model development. Statistical tests such as the Paired Sample T-test, Kruskal–Wallis H-test and Wilcoxon signed-rank test were applied to evaluate the final delineated MZ maps. Additionally, a procedure for improving models based on information about phenological phases and the occurrence of agricultural drought was implemented. The results showed that information on agronomy and climate enables improving and optimizing MZ delineation. The integration of prior knowledge on new climate conditions (drought) in image selection was tested for effective use of the models. Lack of this information led to the infeasibility of obtaining optimal results. Models that solely rely on remote sensing information are comparatively less expensive than hybrid models. Additionally, remote sensing-based models enable delineating MZ for fertilizer recommendations that are temporally closer to fertilization times.

scholarly journals Variable-Rate Application on Fertilizer Use in Cotton Production

2018 ◽  
Vol 10 (10) ◽  
pp. 40
Author(s):  
Nathanael M. Thompson ◽  
James A. Larson ◽  
Margarita Velandia ◽  
Dayton M. Lambert ◽  
Burton C. English
Keyword(s):  
Precision Agriculture ◽  
The United States ◽  
Fertilizer Application ◽  
Variable Rate ◽  
Cotton Production ◽  
Policy Makers ◽  
Factors Affecting ◽  
Fertilizer Use ◽  
The Face ◽  
Input Prices

Precision agriculture technologies are increasingly important in cotton production because input prices continue to rise. Farmers increase input efficiency using precision agriculture technologies by adjusting inputs to match soil fertility and plant nutrition requirements. This research examines the factors affecting changes in fertilizer use following variable-rate fertilizer application in cotton production. Data from a 2009 survey of cotton producers in 12 states of the United States were used in the analysis. Farmers who used precision soil sampling, planted larger cotton area, relied on other farmers for information about PA, grew picker cotton, and had higher household income were more likely to decrease fertilizer application with VRT. Results from this analysis are useful to farmers and policy makers interested in reducing fertilizer use in the face of rising fertilizer prices and growing concerns about the environmental impacts of farming.

Development of a Variable-Rate Controller for a Low-Cost Precision Planter

2020 ◽  
Vol 36 (2) ◽  
pp. 233-243
Author(s):  
Andre L.de F. Coelho ◽  
Daniel M. de Queiroz ◽  
Domingos S.M. Valente ◽  
Francisco A. C. Pinto
Keyword(s):  
Angular Velocity ◽  
Low Income ◽  
Precision Agriculture ◽  
Smallholder Farmers ◽  
Low Cost ◽  
Field Tests ◽  
Planting Density ◽  
Variable Rate ◽  
Management Zones ◽  
Seed Metering Device

HighlightsA low-cost controller for variable-rate seeding was developed.The controller successfully identified management zones and changed the angular velocity of the seed metering device.The variable-rate controller maintained the actual seeding rate according to the prescribed seeding map.Abstract. The use of machines for variable-rate applications is becoming popular in modern agriculture. Due to the presence of imported and complex components, the acquisition cost of these machines is high for smallholder farmers. Several studies have been carried out using low-cost components in the development of precision agriculture machines to facilitate their adoption in low-income agriculture. Thus, the objective of this work was to develop a variable-rate controller for a low-cost precision planter. The system was developed and installed on a 1-row manual planter with a horizontal perforated disk distributor. A direct-current electric motor was used to drive the seed metering device. The angular velocity of the electric motor was controlled by a BeagleBone Black single-board computer. A program was written in Python 3.6 language, and a graphical user interface was generated by using PyQt5. Field trials were performed with maize seeds using a 28-hole disk and a prescription seeding map with four management zones. The row spacing was 0.75 m, and the planter ground speed was close to 1.0 m s-1. Field tests showed that the controller was effective at identifying the four management zones and controlling the angular velocity of the motor. By counting the number of plants germinated in the field test, it was verified that the variation in the angular velocity of the motor produced a change in the planting density. At each management zone, the planting density corresponded to the prescribed seeding map. The total cost of the parts used to assemble the controller was US$337.97, characterizing it as low cost. Successful field tests showed the potential for using low-cost components to develop variable-rate machines for smallholder farmers. Keywords: Low-income agriculture, Management zones, Precision agriculture, Single-board computer, Smallholder farmers.

Crop Yield and Water Use Efficiency as Affected by Different Soil-Based Management Methods for Variable-Rate Irrigation in a Semi-Humid Climate

2018 ◽  
Vol 61 (6) ◽  
pp. 1915-1922
Author(s):  
Xiumei Li ◽  
Weixia Zhao ◽  
Jiusheng Li ◽  
Yanfeng Li
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Irrigation Water ◽  
Irrigation Management ◽  
Variable Rate ◽  
Summer Maize ◽  
Humid Climate ◽  
Management Zones ◽  
Center Pivot ◽  
Use Efficiency

Abstract. To improve the management of variable-rate irrigation (VRI) systems in semi-humid climates, three different soil-based irrigation management methods were evaluated on their potential for reducing irrigation water use and maximizing crop yield and water use efficiency (WUE) during the 2016 and 2017 growing seasons of summer maize in the North China Plain. The three irrigation management methods evaluated were soil water balance modeling (SWB), measured soil water content (SWC), and a combination of SWB and the rain forecast for the next three days (RF). The experiments were implemented on four management zones delineated by available soil water holding capacity of a center-pivot VRI system. A similar irrigation trigger point (70% of field capacity) was used for the three irrigation management methods in the four management zones. In the two seasons, the total water application in the SWC treatments varied in a larger range among the management zones, and the irrigation water applied was 22% and 21% less than in the SWB and RF treatments, respectively. Similar yields were obtained among the irrigation management methods in both seasons. The maximum WUE was always observed with the SWC treatments for the four management zones in the 2017 season. The WUE with the SWC treatments was 36% and 23% higher than with the SWB and RF treatments, respectively. Considering the amount of irrigation water applied, yield, and WUE, our results demonstrated that the SWC method was more suitable for VRI management than the SWB and RF methods in this semi-humid climate. Keywords: Center pivot, Soil water balance, Soil water content, Rain forecast, Summer maize, Yield.

RELATIVE EFFICIENCY OF POINT-INJECTION AND SURFACE APPLICATIONS FOR N FERTILIZATION OF WINTER WHEAT

1990 ◽  
Vol 70 (2) ◽  
pp. 189-201 ◽  
Author(s):  
H. H. JANZEN ◽  
C. W. LINDWALL ◽  
C. J. ROPPEL
Keyword(s):  
Winter Wheat ◽  
Ammonium Nitrate ◽  
Fertilizer N ◽  
N Application ◽  
Fertilizer Use Efficiency ◽  
Fertilizer Use ◽  
Point Injection ◽  
Use Efficiency ◽  
Urea Ammonium Nitrate ◽  
Methods Of Application

Conventional methods of N application for winter wheat often exhibit low fertilizer use efficiency. The comparative effectiveness of a new method, point-injection of N solution, was evaluated in two similar microplot field experiments established in southern Alberta. The first experiment, conducted over three site-year combinations in 1985 and 1986, compared yield response and fertilizer uptake in four spring-applied fertilizer treatments: broadcast urea-ammonium nitrate (UAN), broadcast urea, broadcast ammonium nitrate, and point-injected UAN, all applied in solution form. The second experiment, conducted at five sites in 1987, compared four spring-applied fertilizer treatments: surface-banded UAN, broadcast urea (granular), broadcast ammonium nitrate (granular), and point-injected UAN. All fertilizers were labeled with 15N to permit direct estimation of fertilizer uptake. The experiments demonstrated significant increases in fertilizer efficiency with point-injection under some conditions. In five of eight comparisons conducted over a 3-yr period, point-injection treatments exhibited significantly higher fertilizer use efficiency than conventional broadcast methods of application. Average fertilizer-N recovery by the crop at all eight sites was 37% in the point-injection treatments compared with only 26% in the broadcast ammonium nitrate treatment, the next most effective method of N application. When one site was excluded, because of possible confounding effects of application time, average recoveries were 34 and 26%, respectively. The increased efficiency of point-injected fertilizers was attributed to the direct placement of fertilizer N into the active rooting zone of the crop. The advantage of point-injection over conventional methods of application was highly variable, ranging from approximately 0 to over 100%, in part because of variations in precipitation patterns. The results of these microplot studies suggest that point-injection has potential for significant enhancement of fertilizer use efficiency in winter wheat, particularly in semi-arid production regions. Key words: 15N, nitrogen, urea, ammonium nitrate, fertilizer placement

scholarly journals Site-specific Crop Nutrient Management for Precision Agriculture – A Review

2021 ◽  
pp. 37-52
Author(s):  
Tapan Gorai ◽  
Pankaj Kumar Yadav ◽  
Gopal Lal Choudhary ◽  
Anil Kumar
Keyword(s):  
Remote Sensing ◽  
Management Practices ◽  
Nutrient Management ◽  
Soil Health ◽  
Crop Productivity ◽  
Variable Rate ◽  
Smartphone Apps ◽  
Fertilizer N ◽  
Site Specific ◽  
Use Efficiency

Present irrational crop and nutrient management practices have raised several concerns of high merit. The concerns include low factor productivity or nutrient use efficiency (NUE), declining crop productivity, farmer’s profitability, impaired soil health and ecological contamination. Site-specific nutrient management (SSNM), after considering indigenous nutrient supplying capacity of soil using plant and soil analysis, can feed the crop in synchrony with its nutrient requirement in different physiological growth stages. Besides, several modern geospatial techniques viz. remote sensing techniques, geographic information system (GIS), global positioning system (GPS), proximal sensing; information and communication technologies (ICTs) including decision support system, smartphone apps and web services can also assist in diagnosis of soil and crop nutrient status, fertilizer recommendation and its dissemination to users. Optical and thermal remote sensing can effectively detect crop stress including nitrogen (N) deficiency through several vegetation indices especially normalized difference vegetation index (NDVI). GIS techniques with spatial data acquired by GPS, can create spatial variability map and management zone (MZ) for precise farm operations including variable rate fertilization. Proximal crop sensors viz. chlorophyll meter and Green Seeker can also recognize crop nitrogen status and promote fertilizer N use efficiency by synchronizing fertilizer N supply with crop requirement. Even proximal soil sensing using electromagnetic radiation and contact electrode can estimate soil properties like soil pH, electrical conductivity, major and micronutrient content. Several decision support systems such as QUEFTS based model, crop manager, nutrient expert® and smartphone apps like ‘crop doctor’ can suggest for precise application of agro-inputs to rural youths and farmers. Yield monitoring and mapping tool can generate historical GIS database for spatial variability of crop yield under farmers’ crop management practices and assessment of nutrient uptake. Variable rate machinery based on variability map and sensor technologies can also be used for fertilization under different management zones. Therefore, SSNM technologies can enhance NUE; improve and sustain crop productivity, profitability; avoid nutrient wastage; maintain good soil health and environmental safety.

scholarly journals Nitrogen Accumulation and Fertilizer Use Efficiency by Grapevines in Short-season Growing Areas

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 504-507 ◽  
Author(s):  
Eric J. Hanson ◽  
G. Stanley Howell
Keyword(s):  
Fertilizer Application ◽  
Nitrogen Accumulation ◽  
Fertilizer N ◽  
Fruit Maturation ◽  
Vitis Labrusca ◽  
N Content ◽  
Fertilizer Use ◽  
Native Soil ◽  
Fruit Maturity ◽  
Use Efficiency

Mature `Concord' vines (Vitis labrusca L.) were excavated at 2- to 4-week intervals through the season to study seasonal changes in vine N concentration. Vine N content began increasing 2 weeks after budbreak, increased most rapidly from mid-May to mid-July, and declined between fruit maturation and the beginning of leaf senescence. Vine N content was lowest at budbreak (18 g) and maximum at fruit maturity (75 g). This change represented a net accumulation of 57 g N/vine or 77 kg N/ha. In a separate study, `Seyval blanc' vines were treated with double 15N-labeled ammonium nitrate at either budbreak or bloom. Labeled N was applied as a spray beneath vines to simulate a broadcast vineyard application. Vines were excavated when leaves began to senesce in October, partitioned into various components, and analyzed by mass spectrophotometry to determine fertilizer-derived N content. Vines had recovered statistically similar percentages of fertilizer N applied at budbreak (7.1%) and bloom (10.6%). The low recovery of fertilizer N likely resulted from the method of fertilizer application, the presence of a competitive grass sod between the rows, and relatively high native soil N levels.

Evaluation of Finger Millet Varieties under Rainfed Condition of Eastern India

2017 ◽  
Vol 4 (03) ◽  
Author(s):  
M. K. Singh ◽  
VINOD KUMAR ◽  
SHAMBHU PRASAD
Keyword(s):  
Field Experiment ◽  
Finger Millet ◽  
Yield Potential ◽  
Growing Degree Days ◽  
Eastern India ◽  
Degree Days ◽  
Rainfed Condition ◽  
Net Returns ◽  
Humid Environment ◽  
Use Efficiency

A field experiment was carried out during the kharif of 2014 and 2015 to evaluate the yield potential, economics and thermal utilization in eleven finger millet varieties under the rainfed condition of the sub-humid environment of South Bihar of Eastern India. Results revealed that the significantly higher grain yield (20.41 q ha-1), net returns (Rs 25301) and B: C ratio (1.51) was with the finger millet variety ‘GPU 67’ but was being at par to ‘GPU28’and ‘RAU-8’, and significantly superior over remaining varieties. The highest heat units (1535.1oC day), helio-thermal units (7519.7oC day hours), phenothermal index (19.4 oC days day-1) were recorded with variety ‘GPU 67’ followed by ‘RAU 8’ and ‘GPU 28’ and lowest in ‘VL 149’ at 50 % anthesis stage. Similarly, the highest growing degree days (2100 oC day), helio-thermal units (11035.8 oC day hours) were noted with ‘GPU 67’ followed by ‘RAU 8’ and ‘GPU 28’ at maturity. The highest heat use efficiency (0.97 kg ha-1 oC day) and helio-thermal use efficiency (0.19 kg ha-1 oC day hour) were in ‘GPU 67’ followed by ‘VL 315’.

scholarly journals The Relationship between Soil Electrical Parameters and Compaction of Sandy Clay Loam Soil

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 114
Author(s):  
Katarzyna Pentoś ◽  
Krzysztof Pieczarka ◽  
Kamil Serwata
Keyword(s):  
Electrical Conductivity ◽  
Magnetic Susceptibility ◽  
Precision Agriculture ◽  
Soil Compaction ◽  
Soil Layer ◽  
Soil Parameters ◽  
Soil Electrical Conductivity ◽  
Electrical Parameters ◽  
Management Zones ◽  
Additional Information

Soil spatial variability mapping allows the delimitation of the number of soil samples investigated to describe agricultural areas; it is crucial in precision agriculture. Electrical soil parameters are promising factors for the delimitation of management zones. One of the soil parameters that affects yield is soil compaction. The objective of this work was to indicate electrical parameters useful for the delimitation of management zones connected with soil compaction. For this purpose, the measurement of apparent soil electrical conductivity and magnetic susceptibility was conducted at two depths: 0.5 and 1 m. Soil compaction was measured for a soil layer at 0–0.5 m. Relationships between electrical soil parameters and soil compaction were modelled with the use of two types of neural networks—multilayer perceptron (MLP) and radial basis function (RBF). Better prediction quality was observed for RBF models. It can be stated that in the mathematical model, the apparent soil electrical conductivity affects soil compaction significantly more than magnetic susceptibility. However, magnetic susceptibility gives additional information about soil properties, and therefore, both electrical parameters should be used simultaneously for the delimitation of management zones.

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