scholarly journals Effect of pH on Cucumber Growth and Nutrient Availability in a Decoupled Aquaponic System with Minimal Solids Removal

Horticulturae ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 10 ◽  
Author(s):  
Caroline Blanchard ◽  
Daniel E. Wells ◽  
Jeremy M. Pickens ◽  
David M. Blersch

Decoupled aquaponic systems are gaining popularity as a way to manage water quality in aquaponic systems to suit plant and fish growth independently. Aquaponic systems are known to be deficient in several plant-essential elements, which can be affected by solution pH to either increase or decrease available nutrients. To determine the effect of pH in a decoupled aquaponic system, a study was conducted using aquaculture effluent from tilapia culture tanks at four pH treatments: 5.0, 5.8, 6.5, and 7.0, used to irrigate a cucumber crop. Growth and yield parameters, nutrient content of the irrigation water, and nutrients incorporated into the plant tissue were collected over two growing seasons. pH did not have a practical effect on growth rate, internode length or yield over the two growing seasons. Availability and uptake of several nutrients were affected by pH, but there was no overarching effect that would necessitate its use in commercial systems. Nutrient concentrations in the aquaculture effluent would be considered low compared to hydroponic solutions; however, elemental analysis of leaf tissues was within the recommended ranges. Research into other nutrient sources provided by the system (i.e., solid particles carried with the irrigation water) would provide further information into the nutrient dynamics of this system.

2021 ◽  
Author(s):  
M.H.J.P. Gunarathna ◽  
M.K.N. Kumari

Abstract The optimized subsurface irrigation system (OPSIS) is a newly developed subsurface irrigation system to irrigate upland crops. Although it is already evaluated for few crops using field experiments, further evaluation is required. Since field experiments are tedious, expensive, we need an alternative approach to evaluate the OPSIS. A well-calibrated and validated crop model is a fast-alternative option for developing and evaluating agronomic practices. Therefore, this study aimed to develop the modeling capabilities of APSIM to simulate the OPSIS. We conducted field experiments for three growing seasons (main crop and two ratoons), two planting seasons (spring and summer planting), and two separate crops to collect necessary data for calibration and validation processes. We scripted a new module named "OPSIS" to couple OPSIS to the APSIM engine. We parameterized, calibrated, and validated the APSIM to simulate the growth and yield of sugarcane with OPSIS. After firm parameterization and calibration, APSIM-Sugar can successfully simulate the growth and yield of sugarcane with OPSIS. However, the simulation of soil moisture dynamics and irrigation water use were not up to the standards. Although it gives quite reasonable results for growth and yield simulations of sugarcane, further studies are suggested to develop the simulation accuracy of soil water dynamics and irrigation water use through the OPSIS.


2020 ◽  
pp. 1-12
Author(s):  
E. K. Al-Fahdawe ◽  
A. A. Al-Sumaidaie ◽  
Y. K. Al-Hadithy

A pots experiment was conducted at the Department of Biology/College of Education for Girls/University of Anbar during Autumn season of 2018-2019 to study the effect of the salinity irrigation water and spray by humic acid in some of morphological, physiological, growth and yield traits of wheat cv. IPa. The experiment was randomized complete block design (RCBD) with three replications. The first factor was assigned for irrigation by saline water at four level (S0, S1, S2 and S3), while the second factor was the foliar spraying of humic acid in three level (0.0, 1.0 and 1.5 g l-1). The results showed that there was significant reduction in plant height, vegetative dry weight, biological yield and chlorophyll leaves content when the plants were irrigated by saline water approached to 41.09 cm, 0.747 g, 0.849 g plant-1 and 38.67 SPAD, respectively at salinity level of 8.3 ds m-1 compared with the plants which irrigated by fresh water. The total carbohydrates were significantly decreased at the treatment of 8.3 ds m-1 reached 18.71 mg g-1. Spray levels humic acid achieved a significant increase in plant height, dry weight of the vegetative part, biological yield and chlorophyll leaves content sprayed at 1.0 and 1.5 g l-1 compared to no sprayed. Nitrogen concentration was significantly increased, while both phosphorus and potassium were decreased in the vegetative parts of wheat as the salinity of irrigation water increased. However, the increase of humic acid levels led to significant increasing in nitrogen, phosphorus and potassium concentration.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 550a-550 ◽  
Author(s):  
Royal G. Fader ◽  
Martin J. Bukovac

We have reported that NH4NO3 (AN, 8 mM, pH 4.2), applied as simulated spray droplets, enhanced penetration of 14C-NAA through isolated leaf and fruit cuticles. One explanation for this response is that AN depresses NAA (pKa= 4.2) dissociation, increasing the nondissociated moiety, which penetrates more readily than the anion (NAA'). Direct measurement of AN (concn. 0-800 mM) effect on NAA (215 μM) dissociation as indexed by change in solution pH revealed no significant effect, with a pH change from 4.19 to 4.05. This change is not sufficient to account for the observed enhancement. When 14C-NAA, buffered (20 mM sodium citrate) at pH 3.2, 4.2, 5.2, 6.2, was partitioned against chloroform, there was a marked increase in NAA partitioning into chloroform as pH was decreased. AN (8 mM) did not alter this partition behavior, also indicating no effect on NAA dissociation. However, in cuticle penetration studies, using a finite dose system with 14C-NAA buffered at pH 3.2, 4.2, 5.2, 6.2, and in the presence and absence of 8 mM AN, there was no marked or consistent pH or AN (-70 to + 232 % of no AN control) effect on penetration as indexed by initial slope (4-12 h) or penetration after 120 h. The possible effects of AN and buffer on penetration of 14C-NAA from the droplet deposit will be discussed.


2021 ◽  
pp. 1-25
Author(s):  
Mandy Bish ◽  
Brian Dintelmann ◽  
Eric Oseland ◽  
Jacob Vaughn ◽  
Kevin Bradley

Abstract The evolution of herbicide-resistant weeds has resulted in the necessity to integrate non-chemical control methods with chemicals for effective management in crop production systems. In soybean, control of the pigweed species, particularly herbicide-resistant waterhemp and Palmer amaranth, have become predominant concerns. Cereal rye planted as a winter cover crop can effectively suppress early-season weed emergence in soybean, including waterhemp, when planted at a rate of 123 kg ha−1. The objectives of this study were to determine the effects of different cereal rye seeding rates (0, 34, 56, 79, 110, and 123 kg ha−1) on early-season waterhemp suppression and soybean growth and yield. Soybean was planted into fall-seeded cereal rye, which was terminated within four days of soybean planting. The experiment was conducted over the 2018, 2019, and 2020 growing seasons in Columbia, Missouri. Effects of cereal rye on early-season waterhemp suppression varied by year and were most consistent at 56 kg ha−1 or higher seeding rates. Linear regression analysis of cereal rye biomass, height, or stand at soybean planting showed inverse relationships with waterhemp emergence. No adverse effects to soybean growth or yield were observed at any of the cereal rye seeding rates relative to plots that lacked cereal rye cover. Result differences among the years suggest that the successfulness of cereal rye on suppression of early-season waterhemp emergence is likely influenced by the amount of waterhemp seed present in the soil seed bank.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 228
Author(s):  
Ikram Ullah ◽  
Hanping Mao ◽  
Ghulam Rasool ◽  
Hongyan Gao ◽  
Qaiser Javed ◽  
...  

This study was conducted to investigate the effects of various irrigation water (W) and nitrogen (N) levels on growth, root-shoot morphology, yield, and irrigation water use efficiency of greenhouse tomatoes in spring–summer and fall–winter. The experiment consisted of three irrigation water levels (W: 100% of crop evapotranspiration (ETc), 80%, and 60% of full irrigation) and three N application levels (N: 100%, 75%, and 50% of the standard nitrogen concentration in Hoagland’s solution treatments equivalent to 15, 11.25, 7.5 mM). All the growth parameters of tomato significantly decreased (p < 0.05) with the decrease in the amount of irrigation and nitrogen application. Results depicted that a slight decrease in irrigation and an increase in N supply improved average root diameter, total root length, and root surface area, while the interaction was observed non-significant at average diameter of roots. Compared to the control, W80 N100 was statistically non-significant in photosynthesis and stomatal conductance. The W80 N100 resulted in a yield decrease of 2.90% and 8.75% but increased irrigation water use efficiency (IWUE) by 21.40% and 14.06%. Among interactions, the reduction in a single factor at W80 N100 and W100 N75 compensated the growth and yield. Hence, W80 N100 was found to be optimal regarding yield and IWUE, with 80% of irrigation water and 15 mM of N fertilization for soilless tomato production in greenhouses.


1984 ◽  
Vol 64 (1) ◽  
pp. 139-146
Author(s):  
THERON G. SOMMERFELDT

The effects of soil and solution pH and Na:Ca ratio in solution on the exchangeable Na, Ca, and (Na + Ca) of a Na-saturated Dark Brown Chernozemic soil were studied. At soil pH 9.0, the exchangeable Na, Ca, and (Na + Ca) were 14.5, 25.4, and 21.8% greater than at soil pH 6.0. Solution pH (6.0–9.0) had small but statistically significant effects on the amount of Na and Ca adsorbed by the soil. The logarithm of exchangeable sodium percentage (ESP) was related to the Na fraction in the solution by a polynomial equation, log ESP = 0.93 [Na/(Na + Ca)]2 + 0.16 [Na/(Na + Ca)] + 0.82. Not only is replacement of exchangeable Na with Ca important in the reclamation of this soil, should it become sodic and have a high pH, but also lowering of its surface charge, through lowering of its pH, would be an important factor in its reclamation. It appears impractical to reduce soil pH by applying acidified irrigation water. Acidic amendments such as gypsum and sulfur may be more suitable. Key words: Cation exchange, solution pH, soil pH


2021 ◽  
Author(s):  
Victor Burgeon ◽  
Julien Fouché ◽  
Sarah Garré ◽  
Ramin Heidarian-Dehkordi ◽  
Gilles Colinet ◽  
...  

&lt;p&gt;The amendment of biochar to soils is often considered for its potential as a climate change mitigation and adaptation tool through agriculture. Its presence in tropical agroecosystems has been reported to positively impact soil productivity whilst successfully storing C on the short&amp;#8201;and long-term. In temperate systems, recent research showed limited to no effect on productivity following recent biochar addition to soils. Its long-term effects on productivity and nutrient cycling have, however, been overlooked yet are essential before the use of biochar can be generalized.&lt;/p&gt;&lt;p&gt;Our study was set up in a conventionally cropped field, containing relict charcoal kiln sites used as a model for century old biochar (CoBC, ~220 years old). These sites were compared to soils amended with recently pyrolyzed biochar (YBC) and biochar free soils (REF) to study nutrient dynamics in the soil-water-plant system. Our research focused on soil chemical properties, crop nutrient uptake and soil solution nutrient concentrations. Crop plant samples were collected over three consecutive land occupations (chicory, winter wheat and a cover crop) and soil solutions gathered through the use of suctions cups inserted in different horizons of the studied Luvisol throughout the field.&lt;/p&gt;&lt;p&gt;Our results showed that YBC mainly influenced the soil solution composition whereas CoBC mainly impacted the total and plant available soil nutrient content. In soils with YBC, our results showed lower nitrate and potassium concentrations in subsoil horizons, suggesting a decreased leaching, and higher phosphate concentrations in topsoil horizons. With time and the oxidation of biochar particles, our results reported higher total soil N, available K and Ca in the topsoil horizon when compared to REF, whereas available P was significantly smaller. Although significant changes occurred in terms of plant available nutrient contents and soil solution nutrient concentrations, this did not transcend in variations in crop productivity between soils for neither of the studied crops. Overall, our study highlights that young or aged biochar behave as two distinct products in terms of nutrient cycling in soils. As such the sustainability of these soils differ and their management must therefore evolve with time.&lt;/p&gt;


2002 ◽  
Vol 46 (8) ◽  
pp. 59-66 ◽  
Author(s):  
E. Okuş ◽  
A. Aslan-Yilmaz ◽  
A. Yüksek ◽  
S. Taş ◽  
V. Tüfekçi

As part of a five years monitoring project “Water Quality Monitoring of the Strait of Istanbul”, February-December 1999 nutrient dynamics of the Black Sea-the Sea of Marmara transect are studied to evaluate the effect of discharges given by deep disposals. Through a one-year study, upper layer nutrient concentrations were generally under the effect of northwestern-shelf Black Sea originated waters. This effect was strictly observed in July, when the upper layer flow was the thickest. On the other hand, partly in November but especially in December the northwestern-shelf Black Sea originated water flow was a minimum resulting in similar concentrations in both layers. Nutrient fluctuations also affected the chlorophyll a and POC concentrations as parameters of productivity. The nutrient concentrations decreased with the effect of spring bloom and highest chlorophyll a values were detected in November at Strait stations that did not match to the Sea of Marmara values. This fact represents the time-scale difference between the Black Sea and the Sea of Marmara. On the contrary, high nutrient concentrations in the lower layer (especially inorganic phosphate), and therefore low N:P ratios reflect the effect of deep discharge. Vertical mixing caused by meteorological conditions of the shallow station (M3) under the effect of surface discharges resulted in homogenous distribution of nutrients. Nutrient concentrations of the stations affected by deep discharge showed that the two-layer stratification of the system did not permit the discharge mix to the upper layer.


Weed Science ◽  
1992 ◽  
Vol 40 (3) ◽  
pp. 460-464
Author(s):  
Ken M. Nawolsky ◽  
Ian N. Morrison ◽  
George M. Marshall ◽  
Allen E. Smith

The relationships between the actual amount of spring-applied trifluralin detected in soil at seeding, initial injury to flax, and crop growth and yield were investigated in southern Manitoba over three growing seasons. As the amount of trifluralin in the soil increased, flax density and dry matter production decreased, such that at a soil concentration equivalent to 1 kg ai ha−1trifluralin, the two were reduced by 40 and 49%, respectively. Recovery from early-season injury was characterized by enhanced crop growth rates (CGRs) and net assimilation rates (NARs) of surviving plants during the remainder of the growing season. Maximum recovery occurred in plots where trifluralin levels in the soil were between 0.8 and 1 kg ha−1at seeding. During the interval between stem elongation and bud initiation, CGRs and NARs of flax in the trifluralin-treated plots exceeded those of flax in the untreated plots by up to 1.5 and 1.2 times, respectively. Additionally, the number of branches per plant increased linearly as trifluralin amounts in the soil increased. Flax seed yield was decreased by trifluralin as described by the equation: flax seed (% of untreated control) = 104.9 - 13.3[trifluralin detected (kg ha−1) at seeding]. Based on this equation, trifluralin levels in the soil of up to 0.7 kg ai ha−1caused less than a 5% reduction in flax yield under weed-free conditions.


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