scholarly journals Effect of Humic Acid Addition on Buffering Capacity and Nutrient Storage Capacity of Soilless Substrates

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingcheng Xu ◽  
Esraa Mohamed ◽  
Qiang Li ◽  
Tao Lu ◽  
Hongjun Yu ◽  
...  

Excessive application of fertilizers has become a major issue in croplands of intensive agricultural systems in China, resulting in severe non-point source pollution; thus, reduction in the use of chemical fertilizers has received significant attention. Improving the nutrient storage capacity of soils or substrates is an effective approach for solving this problem. Humic acids (HA) are excellent soil conditioners. Thus, in the present study, their ability to improve the physico-chemical properties of three substrates with different textures was evaluated. HA treatments included 1% HA root application in three different types of substrates, including pure sand, pure cocopeat, and a mixture of sand:cocopeat (1:1, v/v) and their relative controls. We examined the morphological parameters of cucumber seedlings as well as pH buffering capacity (pHBC), total organic carbon (TOC), organic matter (OM), cation exchange capacity (CEC), and nutrient storage capacity of the three substrates. The results show that HA application improved the morphological parameters of cucumber seedlings (plant height, stem diameter, and biomass) in pure cocopeat and cocopeat-sand mixture treatments. On the contrary, HA addition had harmful effects on the cucumber seedlings cultivated in sand due to the low pHBC of sand. The seedlings cultivated in pure cocopeat showed the best morphological parameter performances among the seedlings grown in the three substrates. Furthermore, pHBC, TOC, OM, and CEC were enhanced by HA application. Incorporation of HA improved ammonium (NH4+) and potassium (K+) storage capacity while decreasing phosphorus (P) storage. Pure cocopeat had the highest pHBC, TOC, OM, CEC, and nutrient storage capacity among the three substrates. In conclusion, mixing 1% HA into substrates promoted cucumber growth, improved substrate properties, and enhanced fertilizer use efficiency. Pure cocopeat is a suitable substrate for cucumber cultivation, and mixing cocopeat with sand amends the substrate properties and consequently improves plant growth.

2018 ◽  
Vol 42 (6) ◽  
pp. 445-449 ◽  
Author(s):  
Sudharani A Pyati ◽  
R Naveen Kumar ◽  
Vinod Kumar ◽  
N H Praveen Kumar ◽  
K M Parveen Reddy

Objectives: To measure and compare the levels of salivary flow rate, pH, buffering capacity, total protein, malondialdehyde (MDA) and total antioxidant capacity (TAC) between caries active and caries free children and to study the correlation between the DMFS/dfs score and above salivary parameters in caries active children. Study design: 50 caries active (DMFS/dfs ≥ 5) and 50 caries free (DMFS/dfs = 0) children aged between 6 to 12 years were included in the study. From all the children, unstimulated, mid-morning saliva samples were collected and salivary flow rate was calculated. Salivary pH, buffering capacity, total protein, MDA and TAC were measured. Results: The mean levels of salivary flow rate, pH, buffering capacity were significantly decreased (p < 0.05) and total protein, MDA and TAC were significantly increased (p < 0.05) in caries active children when compared to caries free controls. There was a proportionate decrease (p < 0.05) in salivary flow rate, pH and buffering capacity and proportionate increase (p > 0.05) in salivary total protein, MDA and TAC as DMFS/dfs score increased in caries active children. Conclusions: Significant alteration in the levels of salivary flow rate, pH, total proteins, MDA and TAC and their correlation with DMFS/dfs score in caries active children suggest, the levels of these physico-chemical properties of saliva can act as strong indicators of caries status in children.


Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 379
Author(s):  
Perumal Palanivell ◽  
Osumanu Haruna Ahmed ◽  
Latifah Omar ◽  
Nik Muhamad Abdul Majid

The physical and chemical properties of clinoptilolite zeolite can be used to enhance soil nutrient availability for optimum crop use. Amending nitrogen, phosphorus, and potassium fertilizers with clinoptilolite zeolite could create a pool of negative charges to retain and release nutrients timely for crop use. Thus, we used clinoptilolite zeolite to enhance Typic Paleudults sorption (adsorption and desorption) of nitrogen, phosphorus, potassium, and this soil’s pH buffering capacity. The treatments evaluated were: (i) 250 g soil alone, (ii) 20 g clinoptilolite zeolite alone, (iii) 250 g soil + 20 g clinoptilolite zeolite, (iv) 250 g soil + 40 g clinoptilolite zeolite, and (v) 250 g soil + 60 g clinoptilolite zeolite. Clinoptilolite zeolite increased soil nitrogen and potassium adsorption, nitrogen desorption, and soil pH. Moreover, ability of the soil to resist drastic change in pH (pH buffering capacity) was improved. Additionally, phosphorus adsorption and desorption of phosphorus and potassium were reduced. Higher potassium adsorption with lower potassium desorption suggests that the clinoptilolite zeolite sorbs potassium effectively. The clinoptilolite zeolite nitrogen, phosphorus, and potassium contributed to the reduction in the adsorption these nutrients. The clinoptilolite zeolite improved nitrogen, phosphorus, and potassium availability and soil buffering capacity to prevent these nutrients from being fixed or lost through for example, leaching. Therefore, clinoptilolite zeolite application could contribute to improved use of nitrogen, phosphorus, and potassium fertilizers to prevent soil, air, and water pollution. Additionally, our intervention could improve nitrogen, phosphorus, and potassium use efficiency.


Horticulturae ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 14 ◽  
Author(s):  
Lan Huang ◽  
Mengmeng Gu

Biochar refers to a processed, carbon-rich material made from biomass. This article provides a brief summary on the effects of biochar on container substrate properties and plant growth. Biochar could be produced through pyrolysis, gasification, and hydrothermal carbonization of various feedstocks. Biochar produced through different production conditions and feedstocks affect its properties and how it performs when incorporated in container substrates. Biochar incorporation affects the physical and chemical properties of container substrates, including bulk density, total porosity, container capacity, nutrient availability, pH, electrical conductivity and cation exchange capacity. Biochar could also affect microbial activities. The effects of biochar incorporation on plant growth in container substrates depend on biochar properties, plant type, percentage of biochar applied and other container substrates components mixed with biochar. A review of the literature on the impact of biochar on container-grown plants without other factors (such as irrigation or fertilization rates) indicated that 77.3% of the studies found that certain percentages of biochar addition in container substrates promoted plant growth, and 50% of the studies revealed that plant growth decreased due to certain percentages of biochar incorporation. Most of the plants tested in these studies were herbaceous plants. More plant species should be tested for a broader assessment of the use of biochar. Toxic substances (heavy metals, polycyclic aromatic hydrocarbons and dioxin) in biochars used in container substrates has rarely been studied. Caution is needed when selecting feedstocks and setting up biochar production conditions, which might cause toxic contaminants in the biochar products that could have negative effects on plant growth.


2019 ◽  
Vol 10 (1) ◽  
pp. 295
Author(s):  
Perumal Palanivell ◽  
Osumanu Haruna Ahmed ◽  
Omar Latifah ◽  
Nik Muhamad Abdul Majid

Adsorption and desorption of nitrogen (N), phosphorus (P), and potassium (K) soils are controlled by pH, pH buffering capacity, organic matter, and cation exchange capacity (CEC). These factors optimized to improve timely availability of N, P, and K crop use using organic amendments such as chicken litter biochar (CLB). The objective of this study was to determine the effects of CLB on N, P, K sorption and pH buffering capacity of an acid soil. Different rates of CLB were mixed with an acid soil for N, P, and K sorption and pH buffering capacity determination. The CLB increased soil pH and pH buffering capacity, but unlike P and K adsorption, the different rates of CLB significantly increased N adsorption, suggesting that this soil amendment has high affinity for N than P and K. Also, because CLB reduced N, P, and K desorption, it suggests that N in particular will be slowly released with time. The reduced N desorption but higher N adsorption further indicates that N can be temporary fixed by CLB. This work has revealed CLB is more effective controlling soil N availability for timely crop use to avoid losses.


2020 ◽  
Vol 15 (No. 2) ◽  
pp. 93-100 ◽  
Author(s):  
Fibrianty Minhal ◽  
Azwar Ma'as ◽  
Eko Hanudin ◽  
Putu Sudira

The main problem with coastal sandy soil is its low water and nutrient retention due to its low clay and organic matter content. This study was aimed at improving the chemical properties and buffering capacity of these soils by using ameliorants of clay and organic polymers. The leaching experiment was conducted with two factors and three replications. The first factor was a clay ameliorant (5% clay, whether from the soil type Inceptisol (I) and the soil type Vertisol (V)). The second factor was a natural or synthetic organic polymer (tapioca 1% and 2% (T1 and T2), tapioca dregs 1% and 2% (TD1 and TD2), polyvinyl alcohol 0.1% and 0.2% (P1 and P2)). The leaching was carried out at 1-month intervals and the leachate was collected for the analysis of the soluble Ca, Mg, K and Na. The leaching was stopped after all the treatments reached the electrical conductivity values < 100 μS/cm. The ameliorants of clay (I or V) and natural polymer (T or TD) significantly increased the cation exchange capacity, the available cations, and the buffering capacity of the coastal sandy soil. The single treatment of I was better than V in increasing the available Mg, while the combination with organic natural polymers could increase the available Ca and K. The treatment of ITD2 was able to increase the soil buffering and maintain the soluble Ca, Mg and K in the coastal sandy soil. Therefore, TD which is a by-product of the tapioca flour industry when combined with I has the potential to be a prospective ameliorant for coastal sandy soils.


1998 ◽  
Vol 38 (4-5) ◽  
pp. 29-35 ◽  
Author(s):  
C. J. Banks ◽  
P. N. Humphreys

The stability and operational performance of single stage digestion with and without liquor recycle and two stage digestion were assessed using a mixture of paper and wood as the digestion substrate. Attempts to maintain stable digestion in both single stage reactors were unsuccessful due to the inherently low natural buffering capacity exhibited; this resulted in a rapid souring of the reactor due to unbuffered volatile fatty acid (VFA) accumulation. The use of lime to control pH was unsatisfactory due to interference with the carbonate/bicarbonate equilibrium resulting in wide oscillations in the control parameter. The two stage system overcame the pH stability problems allowing stable operation for a period of 200 days without any requirement for pH control; this was attributed to the rapid flushing of VFA from the first stage reactor into the second stage, where efficient conversion to methane was established. Reactor performance was judged to be satisfactory with the breakdown of 53% of influent volatile solids. It was concluded that the reactor configuration of the two stage system offers the potential for the treatment of cellulosic wastes with a sub-optimal carbon to nitrogen ratio for conventional digestion.


2004 ◽  
Vol 68 (2) ◽  
pp. 662-668 ◽  
Author(s):  
A. R. Weaver ◽  
D. E. Kissel ◽  
F. Chen ◽  
L. T. West ◽  
W. Adkins ◽  
...  

2017 ◽  
Vol 38 (1) ◽  
pp. 143
Author(s):  
Liane Barreto Alves Pinheiro ◽  
Rodrigo Camara ◽  
Marcos Gervasio Pereira ◽  
Eduardo Lima ◽  
Maria Elizabeth Fernandes Correia ◽  
...  

Mound-building termites are important agents of soil bioperturbation, but these species have not been extensively studied thus far. The present study aimed to evaluate the soil particle-size and the chemical attributes of termite mounds and the surrounding soil under different land use strategies. A one-hectare plot was defined for an unmanaged degraded pasture, planted pasture, and for a eucalyptus Corymbia citriodora plantation. In each plot, the top, center, and base sections of five Cornitermes cumulans mounds, and the surrounding soil at the depths of 0-5; 5-10; 10-20 cm, were sampled in the Pinheiral, Rio de Janeiro state. In the three areas, the center of the mounds contained higher clay content, organic carbon, phosphorous, calcium and magnesium, total bases, and cation exchangeable capacity, when compared to the top, base, and the surrounding soils. However, the center had lower values of exchangeable acidity and potassium, of the three areas. In the eucalyptus plantation, the values of pH, total bases, calcium, and magnesium were lower, whereas aluminum, exchangeable acidity, sodium, and cation exchange capacity were higher both in the mounds and in the surrounding soil, in relation to the pastures. There were no differences among the three areas in terms of organic carbon, potassium, phosphorous, and total bases, in the mounds and adjacent soil. Thus, the termite activity altered the clay content and most of the soil chemical properties in all of the studied areas, but only for the center of the mounds. However, the effect of these organisms was different in the eucalyptus plantation in relation to the pasture areas.


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