Charge Characteristics and Cation Exchanges Properties of Hilly Dryland Soils Aceh Besar, Indonesia

Abstract

Soil surface charge and cation exchange are important parameters of soil fertility in tropical soils. This study was conducted to investigate characteristics of surface charges and cation exchanges on four soil orders of the dryland in Aceh Besar district. The soil order includes Entisols Jantho (05o16’58.41” N; 95o37’51.82” E), Andisols Saree (05o27'15.6" N; 95o44'09,1" E), Inceptisols Cucum (05º18’18,37” N; 95º32’48,04” E), dan Oxisols Lembah Seulawah (05o27’19,4” N; 95o46’19,2” E). The charge characteristics of surface charge are evaluated from the parameter of DpH (pHH2O-pHKCl), variable charge (Vc), permanent charge (Pc), and point of zero charges (PZC). In contrast, cation exchange properties are evaluated from several soil chemical properties, such as soil organic matter (SOM), base saturation (BS), cation exchange capacity (CEC), and effective CEC (ECEC). The results show that the four pedons of soil in the hilly dryland of Aceh Besar include a variable charge because it has a PZC, which is characterized by a negative surface charge with a PZC of pHH2O and has CEC dependent soil pH. PZC value varies from 3.21 – 5.26 and sequentially PZC Andisols Oxisols Entisols Inceptisols. The total CEC value differs considerably from ECEC and the sum of cations. CEC total of the soils varies from 12.8 – 34.4 cmol kg-1, whereas the ECEC values vary from 2.72 – 8.66 cmol kg-1. The highest variable charge percentage is found in Andisols Saree. In contrast, the highest permanent charge is found in Inceptisols Cucum and is positively correlated with pHH20, PZC, CEC, and sums of cations or ECEC. Improving soil quality in hilly dryland soils in Aceh Besar District can be done by decreasing the PZC status of soils with organic amendments and fertilizers or increasing the pH by using liming.

Assessment of carbon and nitrogen distribution on several soil orders for sustainable management in dryland farming: A Case Study in Aceh Besar Regency, Indonesia

“…Entisols of Aceh Besar have moderate to low SOC content. This soil order is found in hilly to steep topography with a high slope of >40% and has a shallow solum thickness of ~30-40 cm [10] and belongs to the subgroup Typic Udorthens. Entisols found in dryland agricultural lands in Aceh Besar are generally found in complex forms with other soil orders such as Ultisols, Inceptisols, and Andisols.…”

“…The second order of soils containing high SOC is Mollisols (Table 1). The average SOC content varied from moderate criteria (36.77±3.08 g kg -1 to very low (4.79±0.44 g kg -1 ) in the deeper soil layers (from 0 to 100 cm) The order Mollisols found in the dry land of Aceh Besar is one of the soil orders with a narrow distribution [10]. This soil is formed from limestone parent material with a moderate soil development level.…”

“…Inceptisols, Oxisols, and Ultisols are those found in Aceh Besar formed from acid clay parent materials that have progressed moderately (Inceptisols) to very advanced (Oxisols and Ultisols), and these soils include soils that are low in organic matter and many chemical constraints. such as acidic soil pH, low organic matter, low CEC, and poor nutrients [9,10]. These soils are dominated by mixed clay mineral types between type 1:1 (kaolinite, metahaloysite), and hydrous oxides of Al and Fe so they have a generally low soil CEC so that the uptake of organic fractions lowlands [17].…”

“…According to the estimation by Umar et al in 2021 [7], the sub-optimal dryland in Aceh Besar District, which has an area of 2,974.12 km 2 , is approximately 239,484.63 ha. The soil orders Entisols, Inceptisols, Ultisols, and Oxisols, as well as the orders Andisols and Mollisols, are all present in this sub-optimal dryland [9,10,11]. According to the findings of earlier research, the majority of the soils that predominate in Aceh Besar's dryland region have poor fertility levels [12] and a low to moderate soil quality index [13].…”

“…Recent research findings suggest that several soil quality indicators, including low soil C [14], low CEC, low base saturation [15], and limited availability of nutrients for plants [9], might be the cause of soil infertility in some drylands. The availability of cation nutrients like Ca, Mg, and K are also reduced due to the low SOM content, which is shown by the low negative charge on the surface of soil colloids [16,10]. As a result, they are less available to plants [17] so leaching is easy.…”