Productivity and water relations of field-grown cashew: a comparison of sprinkler and drip irrigation

2001 ◽  
Vol 41 (5) ◽  
pp. 663 ◽  
Author(s):  
S. J. Blaikie ◽  
E. K. Chacko ◽  
P. Lu ◽  
W. J. Müller
Keyword(s):  
Linear Relationship ◽  
Surface Area ◽  
Drip Irrigation ◽  
Root Zone ◽  
Leaf Gas Exchange ◽  
Stomatal Closure ◽  
Dry Season ◽  
Water Application ◽  
Evaporative Demand ◽  
Tropical Regions

Cashew is an emerging crop in the seasonally ‘wet–dry’ tropical regions of northern Australia. In North Queensland flowering and fruiting of cashew coincides with the dry season (May–November). During this period growers sprinkler irrigate at 500 L/tree.week. A 3-year (1996–98) experiment compared this strategy with alternatives, including no irrigation or drip irrigation in which 115 or 230 L/tree.week was applied by drippers placed near the tree trunk and near the canopy drip line throughout the dry season. Measurements of soil water to 1.3 m, leaf gas exchange, chlorophyll fluorescence, tree sap flow and yield were made. Data collected in the first 2 years showed that the water requirement of the trees increased progressively as the crop load and evaporative demand increased during the dry season. During the final year of the study, additional sprinkler and drip treatments, in which water applications were progressively increased during the dry season, were introduced. The productivity of cashew in this experiment was strongly influenced by irrigation treatments, ranging (over all years) from 42 to 160 g nut/m 2 canopy surface area. Depletion of plant-available water in the root zone was associated with a reduction in photosynthesis mediated by partial stomatal closure. These effects of soil drying were evident in all irrigated treatments during the mid and late stages of the dry season but were more severe in treatments receiving the least water. When irrigation was withheld until the mid-stage of the dry season the trees had similar yields to those that were irrigated throughout, emphasising the importance of providing adequate irrigation between nut set and harvest. When rainfall from January to September in each year of the study was taken into account, there was a strong linear relationship between nut yield and water applied (rainfall + irrigation), with each extra kilolitre of water applied resulting in about 6 extra g nut/m 2 canopy surface area. This linear relationship was based on water application in the range 25–50 kL per season. It is possible that if the seasonal water application had exceeded 50 kL the marginal response to extra water may have diminished. Using drippers was slightly more efficient than sprinklers, with drip-irrigated trees requiring about 5% less water applied to achieve a given nut yield. In years when rainfall is average, and subject to other economic factors, growers in North Queensland should aim to irrigate about 500 L/tree.week. In years of low rainfall between January and September it is likely that yield will be improved by applying more irrigation water; high rainfall during these months of the year may reduce the irrigation requirement. In all cases growers should be careful to accurately monitor water applications, particularly when the total (from rainfall + irrigation) exceeds 40 kL/tree for the season.

THE WATER RELATIONS AND IRRIGATION REQUIREMENTS OF OLIVE (Olea europaea L.): A REVIEW

2013 ◽  
Vol 49 (4) ◽  
pp. 597-639 ◽  
Author(s):  
M. K. V. CARR
Keyword(s):  
Water Relations ◽  
Deficit Irrigation ◽  
Root Zone ◽  
Eastern Mediterranean ◽  
Stomatal Closure ◽  
Irrigation Scheduling ◽  
Convincing Evidence ◽  
Background Information ◽  
Evaporative Demand ◽  
Biennial Bearing

SUMMARYThe results of research on the water relations and irrigation needs of olive are collated and summarised in an attempt to link fundamental studies on crop physiology to irrigation practices. Background information on the ecology of the olive (it is native to the coastal areas of the eastern Mediterranean) and on crop development processes are presented, followed by reviews of the influence of water stress on gas exchange (stomatal conductance, photosynthesis and transpiration), crop water requirements, water productivities and irrigation systems. The olive has many attributes that help to protect it against drought, including the morphology of the leaf, and the capacity to conserve water under conditions of high evaporative demand through stomatal closure, osmotic regulation and resistance to cavitation. The concept of ‘deficit irrigation’ has been the subject of much research. Although vegetative growth is restricted, there is no convincing evidence that ‘sustained deficit irrigation’ or ‘regulated deficit irrigation’ or ‘partial root zone drying’ offer any advantages over conventional practices. Water productivities are very variable and difficult to reconcile due, in part, to biennial bearing, tree-to-tree variability and differences in tree population densities. Similarly, no clear consensus has emerged on how best to exploit the sensitivity of trunk expansion to water availability in irrigation scheduling. As production methods for this historical crop are intensified (high-density hedgerows, irrigated and mechanized orchards), so will the need to understand the role that water plays in the production processes become ever more critical.

scholarly journals Estimating Surface and Groundwater Irrigation Potential under Different Conservation Agricultural Practices and Irrigation Systems in the Ethiopian Highlands

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1645
Author(s):  
Abdu Y. Yimam ◽  
Tewodros T. Assefa ◽  
Feleke K. Sishu ◽  
Seifu A. Tilahun ◽  
Manuel R. Reyes ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Drip Irrigation ◽  
Surface Runoff ◽  
Dry Season ◽  
Low Flow ◽  
Water Application ◽  
Ethiopian Highlands ◽  
Irrigation Potential ◽  
Overhead Irrigation ◽  
Surface And Groundwater

This study was conducted at the Dangishta watershed in the Ethiopian highlands to evaluate irrigation potential from surface and groundwater sources under different farming and water application systems. Daily streamflow and the groundwater table were monitored from 2015 to 2017. Shallow groundwater recharge was estimated using the water table fluctuation method. Automated baseflow separation techniques were used to determine the amount of runoff and baseflow from the total streamflow records. The potential of groundwater and runoff to sustain dry season irrigation (i.e., low flow) was evaluated considering two tillage systems (i.e., conservation agriculture, CA; and conventional tillage, CT), and water application (i.e., drip and overhead) systems for major irrigated crops (i.e., onion, garlic, cabbage, and pepper) grown in the Dangishta watershed. We found that the annual groundwater recharge varied from 320 to 358 mm during the study period, which was about 17% to 22% of the annual rainfall. The annual surface runoff depth ranged from 192 to 268 mm from 2015 to 2017. The results reveal that the maximum seasonal irrigable land from groundwater recharge was observed under CA with drip irrigation (i.e., 2251 and 2992 ha from groundwater recharge and surface runoff, respectively). By comparison, in the CT practice with overhead irrigation, the lowest seasonal irrigable land was observed (i.e., 1746 and 2121 ha from groundwater and surface runoff, respectively). From the low flow analysis, about 199 and 173 ha of one season’s irrigable land could be irrigated using the CA and CT systems, respectively, both with drip irrigation. Similarly, two-season overhead irrigation potential from low flow under CA and CT was found to be about 87 and 76 ha, respectively. The dry season irrigable land using low flow could be increased from 9% to 16% using the CA system for the various vegetables, whereas drip irrigation could increase the irrigable land potential by 56% compared to overhead irrigation. The combined use of groundwater recharge and runoff could sustain up to 94% of the dry season low flow irrigation through the combination of the CA system and drip irrigation. Decision makers must consider the introduction of feasible and affordable technologies to make use of groundwater and direct runoff, to maximize the potential of dry season production through efficient and appropriate CA and water management practices.

scholarly journals Understanding variability in greenhouse gas emission estimates of smallholder dairy farms in Indonesia

2021 ◽  
Author(s):  
Titis Apdini ◽  
Windi Al Zahra ◽  
Simon J. Oosting ◽  
Imke J. M. de Boer ◽  
Marion de Vries ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Rainy Season ◽  
Greenhouse Gas Emission ◽  
Dairy Farms ◽  
Dry Season ◽  
Enteric Fermentation ◽  
Tropical Regions ◽  
Population Mean ◽  
Smallholder Dairy ◽  
Smallholder Dairy Farms

Abstract Purpose Life cycle assessment studies on smallholder farms in tropical regions generally use data that is collected at one moment in time, which could hamper assessment of the exact situation. We assessed seasonal differences in greenhouse gas emissions (GHGEs) from Indonesian dairy farms by means of longitudinal observations and evaluated the implications of number of farm visits on the variance of the estimated GHGE per kg milk (GHGEI) for a single farm, and the population mean. Methods An LCA study was done on 32 smallholder dairy farms in the Lembang district area, West Java, Indonesia. Farm visits (FVs) were performed every 2 months throughout 1 year: FV1–FV3 (rainy season) and FV4–FV6 (dry season). GHGEs were assessed for all processes up to the farm-gate, including upstream processes (production and transportation of feed, fertiliser, fuel and electricity) and on-farm processes (keeping animals, manure management and forage cultivation). We compared means of GHGE per unit of fat-and-protein-corrected milk (FPCM) produced in the rainy and the dry season. We evaluated the implication of number of farm visits on the variance of the estimated GHGEI, and on the variance of GHGE from different processes. Results and discussion GHGEI was higher in the rainy (1.32 kg CO2-eq kg−1 FPCM) than in the dry (0.91 kg CO2-eq kg−1 FPCM) season (P < 0.05). The between farm variance was 0.025 kg CO2-eq kg−1 FPCM in both seasons. The within farm variance in the estimate for the single farm mean decreased from 0.69 (1 visit) to 0.027 (26 visits) kg CO2-eq kg−1 FPCM (rainy season), and from 0.32 to 0.012 kg CO2-eq kg−1 FPCM (dry season). The within farm variance in the estimate for the population mean was 0.02 (rainy) and 0.01 (dry) kg CO2-eq kg−1 FPCM (1 visit), and decreased with an increase in farm visits. Forage cultivation was the main source of between farm variance, enteric fermentation the main source of within farm variance. Conclusions The estimated GHGEI was significantly higher in the rainy than in the dry season. The main contribution to variability in GHGEI is due to variation between observations from visits to the same farm. This source of variability can be reduced by increasing the number of visits per farm. Estimates for variation within and between farms enable a more informed decision about the data collection procedure.

scholarly journals Synthesis of a hierarchical nanoporous carbon material with controllable pore size and effective surface area for high-performance electrochemical capacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (24) ◽  
pp. 14516-14527 ◽  
Author(s):  
Bing Hu ◽  
Ling-Bin Kong ◽  
Long Kang ◽  
Kun Yan ◽  
Tong Zhang ◽  
...  
Keyword(s):  
Pore Size ◽  
Linear Relationship ◽  
Specific Capacitance ◽  
Surface Area ◽  
Carbon Material ◽  
High Performance ◽  
Electrode Materials ◽  
Effective Surface Area ◽  
Effective Surface ◽  
Nanoporous Carbon Material

There is an excellent linear relationship between E-SSA and specific capacitance of HNC-IPNs as electrode materials for EDLCs.

Application of Raman Spectroscopy to the Study of Adsorption Effects at Liquid-Solid Interfaces

1982 ◽  
Vol 36 (4) ◽  
pp. 471-473 ◽  
Author(s):  
Klaus Witke
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Tetrachloride ◽  
Adsorption Isotherm ◽  
Minimal Surface ◽  
Linear Relationship ◽  
Surface Area ◽  
Long Range ◽  
Raman Spectra ◽  
Sample Cell ◽  
Minimal Surface Area

A sample cell for investigating suspensions or emulsions by Raman spectroscopy in the optically favorable 90° scattering arrangement is described. The Raman spectra of pyridine in a suspension of Aerosil 200 in carbon tetrachloride are recorded. The adsorption isotherm of pyridine is determined from the intensities of the Raman lines at 1008 and 990 cm−1. Over a long range of coverage a linear relationship exists between reciprocal concentrations of chemisorbed and dissolved molecules. The minimal surface area that is occupied by a chemisorbed molecule is determined to be approximately 0.75 nm2.

Water use efficiency and fruit quality of table grape under alternate partial root-zone drip irrigation

2008 ◽  
Vol 95 (6) ◽  
pp. 659-668 ◽  
Author(s):  
Taisheng Du ◽  
Shaozhong Kang ◽  
Jianhua Zhang ◽  
Fusheng Li ◽  
Boyuan Yan
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Fruit Quality ◽  
Drip Irrigation ◽  
Root Zone ◽  
Table Grape ◽  
Use Efficiency

scholarly journals Water and Nitrogen Productivity of Potato Growth in Desert Areas under Low-Discharge Drip Irrigation

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 970 ◽  
Author(s):  
Pavel Trifonov ◽  
Naftali Lazarovitch ◽  
Gilboa Arye
Keyword(s):  
Drip Irrigation ◽  
Driving Forces ◽  
Root Zone ◽  
Agricultural Soils ◽  
Potato Crop ◽  
Water Productivity ◽  
Potato Production ◽  
N Leaching ◽  
Limiting Factor ◽  
Potato Growth

Narrow profit margins, resource conservation issues and environmental concerns are the main driving forces to improve fertilizer uptake, especially for potatoes. Potatoes are a high value crop with a shallow, inefficient root system and high fertilizer rate requirements. Of all essential nutrients, nitrogen (N) is often limiting to potato production. A major concern in potato production is to minimize N leaching from the root zone. Therefore, the main objective of this study was to examine the potato crop characteristics under drip irrigation with low-discharge (0.6 L h−1) and to determine the optimal combination of irrigation (40, 60, 80, and 100%) and fertigation (0, 50, and 100%) doses. In this study, the 80% (438.6 mm) irrigation dose and a 50% (50 mg N L−1) fertigation dose (W80%F50%) showed that these doses are sufficient for optimal potato yield (about 40 ton ha−1) in conjunction with water and fertilizer savings. Moreover, this treatment did not exhibit any qualitative changes in the potato tuber compared to the 100% treatments. When considering water productivity and yield, one may select a harsher irrigation regime if the available agricultural soils are not a limiting factor. Thus, higher yields can be obtained with lower irrigation and fertigation doses and a larger area.

scholarly journals Hormonal and Hydroxycinnamic Acids Profiles in Banana Leaves in Response to Various Periods of Water Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jalel Mahouachi ◽  
María F. López-Climent ◽  
Aurelio Gómez-Cadenas
Keyword(s):  
Water Stress ◽  
Leaf Gas Exchange ◽  
Stomatal Closure ◽  
Photosynthetic Performance ◽  
Hydroxycinnamic Acids ◽  
Cinnamic Acids ◽  
Gas Exchange Parameters ◽  
Banana Leaves ◽  
Indole 3 Acetic Acid

The pattern of change in the endogenous levels of several plant hormones and hydroxycinnamic acids in addition to growth and photosynthetic performance was investigated in banana plants (Musa acuminatacv. “Grand Nain”) subjected to various cycles of drought. Water stress was imposed by withholding irrigation for six periods with subsequent rehydration. Data showed an increase in abscisic acid (ABA) and indole-3-acetic acid (IAA) levels, a transient increase in salicylic acid (SA) concentration, and no changes in jasmonic acid (JA) after each period of drought. Moreover, the levels of ferulic (FA) and cinnamic acids (CA) were increased, and plant growth and leaf gas exchange parameters were decreased by drought conditions. Overall, data suggest an involvement of hormones and hydroxycinnamic acids in plant avoidance of tissue dehydration. The increase in IAA concentration might alleviate the senescence of survival leaves and maintained cell elongation, and the accumulation of FA and CA could play a key role as a mechanism of photoprotection through leaf folding, contributing to the effect of ABA on inducing stomatal closure. Data also suggest that the role of SA similarly to JA might be limited to a transient and rapid increase at the onset of the first period of stress.

scholarly journals Exploring how groundwater buffers the influence of heatwaves on vegetation function during multi-year droughts

2021 ◽  
Vol 12 (3) ◽  
pp. 919-938
Author(s):  
Mengyuan Mu ◽  
Martin G. De Kauwe ◽  
Anna M. Ukkola ◽  
Andy J. Pitman ◽  
Weidong Guo ◽  
...  
Keyword(s):  
Land Surface ◽  
Forest Canopy ◽  
Climate Models ◽  
Root Zone ◽  
Stomatal Closure ◽  
Capillary Rise ◽  
Vapour Pressure Deficit ◽  
Global Climate Models ◽  
Surface Model ◽  
The Impact

Abstract. The co-occurrence of droughts and heatwaves can have significant impacts on many socioeconomic and environmental systems. Groundwater has the potential to moderate the impact of droughts and heatwaves by moistening the soil and enabling vegetation to maintain higher evaporation, thereby cooling the canopy. We use the Community Atmosphere Biosphere Land Exchange (CABLE) land surface model, coupled to a groundwater scheme, to examine how groundwater influences ecosystems under conditions of co-occurring droughts and heatwaves. We focus specifically on south-east Australia for the period 2000–2019, when two significant droughts and multiple extreme heatwave events occurred. We found groundwater plays an important role in helping vegetation maintain transpiration, particularly in the first 1–2 years of a multi-year drought. Groundwater impedes gravity-driven drainage and moistens the root zone via capillary rise. These mechanisms reduced forest canopy temperatures by up to 5 ∘C during individual heatwaves, particularly where the water table depth is shallow. The role of groundwater diminishes as the drought lengthens beyond 2 years and soil water reserves are depleted. Further, the lack of deep roots or stomatal closure caused by high vapour pressure deficit or high temperatures can reduce the additional transpiration induced by groundwater. The capacity of groundwater to moderate both water and heat stress on ecosystems during simultaneous droughts and heatwaves is not represented in most global climate models, suggesting that model projections may overestimate the risk of these events in the future.

scholarly journals Water saving and yield increase of sugar beet with subsurface drip irrigation

2013 ◽  
Vol 4 (2) ◽  
pp. 85-91 ◽  
Keyword(s):  
Sugar Beet ◽  
Drip Irrigation ◽  
Sugar Content ◽  
Water Saving ◽  
Subsurface Drip Irrigation ◽  
Water Application ◽  
Yield Increase ◽  
Crop Performance ◽  
Subsurface Drip ◽  
Sugar Beet Crop

This study was conducted to evaluate the surface and subsurface drip irrigation (SDI) application effects on sugar beet crop performance, under two levels (100% and 80%) of water application depth. The experimental design was a split plot with four replications. Laterals were set every second crop row (1 m apart), with emitters spaced 1 m apart. In the case of SDI, laterals were buried 0.45 m under the ground. Soil moisture measurements were taken up to 75 cm depth, using the TDR method. The soil water content and the yield characteristics of each treatment were recorded. Irrigation method showed to affect crop performance significantly while water application level was less critical. The experimental results indicated that the subsurface drip irrigation leaded to a greater yield and higher sugar content making significant water saving compared to surface drip irrigation.

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