Introduction
75% of Peruvian exports correspond to fine or flavored cocoa, ranking third as the worlds producer of fine cocoa or flavored; The Ucayali region contributes 8% of the national cocoa production and is one of the three fasting growing regions in recent years (Ministry of Agriculture and Irrigation-MINAGRI, 2016). Therefore, organic cocoa management accounts for approximately 60% of production in Peru and large quantities of compost fertilizers, prepared with different inputs, are used to develop sustainable production that improve soil and cocoa quality, improving its export potential.
Currently, pen_based compost (FC) is not applied or produced; however, research notes that feather-based compost is a bio-bone with excellent characteristics for its high content of organic matter and nitrogen (Florida and Reategui, 2019) and that it shows great potential to be used in agriculture (Florida, 2019), particularly in crops that require low but constant amounts of nitrogen, as evidenced in organic tobacco (Bennett et al., 2018; Vann et al., 2017) and cocoa that responds negatively to excess fertilization (Puentes et al., 2014) could show positive results regarding the application of this bio-fertilize.
There is evidence that its application in agriculture functions as semi-slow release fertilizer of its components, in particular nitrogen (Adetunji et al., 2012), significantly improve water retention capacity (Tamreihao et al., 2019), the pH, OM, N, P and K+ (Bhange et al., 2016) and about population of hydrolyzing cellulose bacteria and proteolytics, favoring the breakdown of organic matter (Esmaeilzadeh and Gholamalizadeh, 2014). In this context, the research assessed the effect of the application of compost made with 30% broiler chicken feathers on the main chemical indicators of the soil in a CCN-51 cocoa plantation.
Material and methods
Location and weather conditions
The project was developed between September 2018 and July 2019, at the Florida & Cárdenas foundation facility in the town of Nuevo Progreso, located at coordinates UTM 445638 E and 9015391N; (8°54'23.08"S y 75°29'34"O) Politically belongs to the Padre Abad distric and province Ucayali- region Peru . The climatic conditions in which this project was developed have an average annual rainfall of 2,500 mm and 26.5 °C, with a bimodal regime; The highest rainfall occurs between September-April and the minimums between May-August. The experimental area is located at an altitude of 288 meters above sea level and is located in the Omagua ecoregion,or low jungle according to the classification of Pulgar (2014).
Installation of the experimental area
The area has a plantation of Creole cocoa grafted with buds of the CCN-51 clone, five years of installation, the estrangement between rows and plants is 3 m, the terrain has a soft slope of about 2-5%, of the medium terrace Non-floodable with a strongly acidic soil characteristic of subtropical areas (Table 1). The experimental units are 9 x 6 m, include 6 cocoa plants and an area of 54 m2 make a total of 16units and an area of 1 287 m2.
Compost application
Compost has been made with 70% beef manure and 30% feathers as recommended produced by Florida and Reategui company O&D Innovation Sustainable EIRL and applied in three partial doses (September and December 2018 and April 2019); the total applied by treatment was: FC1 absolute witness, FC2 compost of feathers at a rate of 2,000 kg. ha-1, FC3 compost of feather at a rate of 4,000 kg. ha-1 and FC4 compost of feather at a rate of 6,000 kg ha-1. The criterion of the amount applied had as references Florida et al. (2018), Alvarado (2016) and Puentes et al. (2014).
Characterization of compost and soil
The characterization of the FC (Table 2) was carried out in the soil laboratory of the National Agricultural University of the forest (a sample before each application), the parameters for both feather compost and soil samples were: Nt with the Kjendhal method (Bremmer 1965), pH by electrometric method (1: 2.5), dry base OM (for compost) by the acid digestion method and in soil by Walkley and black; P by Metavanadate and UV-Visible spectrum and Ca+2, Mg+2, K+ and Al3+ by extraction with ammonium acetate (Bazán, 2017); for available soil cadmium was used as an extractant EDTA 0.05 M, following mite's methodology (2010), the readings were performed on atomic emission spectrum with inductively coupled plasma ICP OES (HORIBA, Ultima Expert).
Experimental design and statistical analysis
It corresponds to an experimental design, with DBCA arrangement consisting of four treatments (FC 1, FC2, FC3 and FC4) and four repetitions with a total of 16 experimental units. Variance analysis with a significance level p <0.05 was performed using general linear model procedures to determine significant differences between treatments, with the help of statistical software (IBM SPSS 22-2015). The results of the chemical indicators are shown as the average of each treatment for the comparison of mean treatments. The Duncan test was used, with a significance level of p <0.05.
Results
Table 1, shows the results of the soil analysis of the experimental field at the start of the experiment according, to Bazán (2017) and SAGARPA (2012) presents: pH strongly acid, mean content in OM, N, P, K+, Mg2+ and low in Ca2+ and CEC. In addition, it has a changeable acid (CA) and a very high level of Al3+, levels considered to be toxic for most crops.
Table 2 shows the results of the FC analysis made with 70% beef manure and 30% chicken or broiler feathers , according to the recommendations by the company M&F Organics, made prior to each application of the compost (three applications), it shows a pH slightly alkaline, high OM and N content, the other indicators evaluated are considered normal according to the Colombian Technical Standard-NTC 5167 (2011).
Indicators | Concentration |
---|---|
pH | 7.9±0.19 |
OM % | 46.71±3.18 |
N % | 4.35±0.42 |
P2O5 % | 0.65±0.11 |
K % | 1.3±0.24 |
Ca % | 1.53±0.08 |
Mg % | 0.78±0.1 |
Na % | 0.46±0.04 |
Cu μg. g-1 | 39±5.84 |
Fe μg. g-1 | 3080±69.47 |
Mn μg. g- | 196±12.49 |
Zn μg. g-1 | 82±7.91 |
Source: elaborated by the authors.
The general results of the effect of the treatments are described in Table 3, there is a decrease in the exchangeable aluminum (Al3+), changeable acids (CA) and the cation exchange capacity (CEC) and increase in organic matter (OM), nitrogen total (N), phosphorus (P), and potassium (K+), according to the proportion of compost applied, these indicators presented significant differences (p <0.05); the pH, Ca2+, Mg2+ and available cadmium did not present significant differences (p <0.05).
Indicators | Treatments | Statistics | ||||
---|---|---|---|---|---|---|
FC1 | FC2 | FC3 | FC4 | MSE | p | |
pH | 4.02±0.186a | 4.09±0.16a | 4.22±0.07a | 4.09±0.12a | 0.02 | 0.274 |
OM % | 3.05±0.16a | 4.31±0.16c | 4.55±0.18c | 3.72±0.2b | 0.03 | < 0.001 |
N % | 0.16±0.01a | 0.22±0.01c | 0.23±0.012c | 0.19±0.013b | 0.00 | < 0.001 |
P μg. g-1 | 7.5±0.22a | 8.06±0.27bc | 7.78±0.1ab | 8.2±0.24c | 0.047 | 0.003 |
K μg. g-1 | 187±5b | 183±3.42ab | 190±6.24b | 179±2.58a | 20.563 | 0.029 |
Ca Cmol. kg-1 | 1.43±0.17a | 1.3±0.08a | 1.28±0.15a | 1.15±0.17a | 0.022 | 0.129 |
Mg Cmol. kg-1 | 0.48±0.1a | 0.48±0.1a | 0.53±0.1a | 0.48±0.1a | 0.009 | 0.844 |
Al Cmol. kg-1 | 5.14±0.01b | 6.15±0.02c | 4.62±1.03b | 3.34±0.52a | 0.329 | < 0.001 |
CEC Cmol. kg-1 | 8.53±0.58b | 10.27±0.43c | 8.34±1.26b | 5.81±0.42a | 0.571 | < 0.001 |
AC % | 77.75±1.5b | 82.71±1.34b | 77.86±5.16b | 71.93±4.82a | 13.45 | 0.011 |
Cd μg. g-1 | 0.197±0.04a | 0.227±0.03a | 0.2±0.02a | 0.21±0.03a | 0.001 | 0.527 |
FC1 = absolute control (without compost), FC2 = feather compost at 2000 kg. ha-1, FC3 feather compost at the rate of4000 kg. ha-1 and FC4 feather compost at a rate of6000 kg. ha-1. The means followed by the same letter on the line do not differ from each other by Duncan's test, p < 0.05. MSE mean square error.
Source: elaborated by the authors.
Table 4 shows the multiple comparisons to determine the effect of the treatments with respect to the control treatment. For this, the honest significant difference Tukey's HSD was used; the test suggests that the FC2 treatments presented the greatest differences with respect to the control in the available cadmium in the soil, the FC3 treatment in the content of OM and N, Mg2+ and Ca2+ and the FC4 treatment in the content of P, K+, Al3+ and CEC.
Indicador | Tratamientos | Sig. | ||
---|---|---|---|---|
OM | FC1 | FC2 FC3 FC4 | < 0.001 < 0.001 0.001 | |
N | FC1 | FC2 FC3 FC4 | < 0.001 < 0.001 0.006 | |
P | FC1 | FC2 FC3 FC4 | 0.015 0.309 0.003 | |
K+ | FC1 | FC2 FC3 FC4 | 0.611 0.745 0.143 | |
Mg2+ | FC1 | FC2 FC3 FC4 | 1 0.879 1 | |
Al3+ | FC1 | FC2 FC3 FC4 | 0.113 0.598 0.004 | |
CEC | FC1 | FC2 FC3 FC4 | 0.03 0.983 0.001 | |
CA | FC1 | FC2 FC3 FC4 | 0.273 0.1 0.167 | |
Cd2+ | FC1 | FC2 FC3 FC4 | 0.504 0.993 0.967 |
FC1 = absolute control (without compost), FC2 = feather compost at 2000 kg. ha-1, FC3 feather compost at the rate of4000 kg. ha-1 and FC4 feather compost at a rate of6000 kg. ha-1.
Source: elaborated by the authors.
Discussion
Response of chemical Indicators
According to Table 3, no significant differences were found between the different treatments for pH, Ca2+, Mg2+ and Cd2+ ;indicators; This result is partially related to some works such as that of Florida et al (2018) who point out that the application of cowure compost showed no significant effects for Ca2+, Mg2+ and Cd2+, but found differences for pH, producing an increase, Although this does not change the critical level (strongly acidic). Also, Firme et al. (2014) point out that the application of organic amendments significantly improves the pH. However, Torres (2018) applying hen and vacancy found significant increases in pH values (from 4.58 to 4.83); also, Ramírez et al. (2015) with the application of worm humus found the same behavior. Therefore, the means found in this work show an increase from 4.02 FC1 to 4.22 in FC3 with the application of pen compost, although no significant difference was found and the critical level of strongly acidic pH did not vary, evidence, which has the same effect as a compost produced with other inputs as indicated by the references cited.
The results (Table 3) show increases in organic matter (MO), nitrogen N, phosphorus P, potassium(K) and CEC, depending on the proportion of compost applied, these indicators had significant differences and can be explained taking into account the high levels of OM and N according to the proximal analysis of the FC (Table 2). These high levels of OM and N are consisten with what is reported by Florida and Reategui (2019); in addition, according to Bhange et al. (2016) the application of the FC significantly improves the soil OM, N, P and K levels are not high in proximal FC analysis, their decomposition resistance noted by Hadas and Kautsky (1994) and its semi-slow release of its components (Adetunji et al., 2012) promote and adequate incorporation into the soil and increase the levels of some nutrients such as P, K and others. Also, its high OM content may be increasing exchange sites and forming stable complexes (Cortes et al., 2016; Firme et al., 2014), favoring the retention and increase of the main interchangeable cations.
In general, the application of compost based on different inputs has similar effects as the FC on the soil, as well Firme et al. (2014) found significant differences in OM and CIC. Also, Alvarado (2016) showed significant effect on organic matter and phosphorus; Ramírez et al. (2015) with worm humus and manure, found a positive effect and increased the contents of OM, P and K+; Gracia (2012) found changes in the content of OM, macro and micronutrients; Orozco and Muñoz (2011) with chicken increased OM and CEC. Therefore, the results found show great potential for FC for use in agriculture.
Reducing interchangeable aluminium
The soils of the experimental area correspond to strongly acidic soils (Table 1), typical of sub-tropical soils of high rainfall in which the levels of aluminum toxicity are high. About this, Carreño and Chaparro (2013) they point out that aluminum toxicity is the first factor that limiting crop production in acidic soils, because 50% of the potentially arable soil is acidic, particularly soils with warm and humid conditions of the tropical southern belt in which Peru is located; in these types of soils acidity is mainly a consequence of interchangeable aluminum (Castro and Munevar, 2013),because under conditions of acidic soil at pH less than 5.5, Al3+ aluminum ions are solubilized and can penetrate root cells, which inhibits root growth and hinders the absorption of water and essential nutrients such as phosphorus and calcium (Carreño and Chaparro, 2013)
The results in Table 3 show a sustained trend of Al3+ reduction from 5.14 FC1 to 3.34 Cmol. Kg-1 in FC4, reducing by 35.01% on average, this behavior is attributable to the capacity to complex inorganic materials by OM (Martínez et al., 2008), reducing mobility factors by producing an increase in exchange sites, forming stable complexes, mineral precipitation and ion exchange (Cortes et al., 2016; Firme et al., 2014). These interactions improve the availability of P, block potential reaction sites with Fe, Al and Ca (Martínez et al., 2008) and increase the retention capacity of different soil metals (Firme et al., 2014). There is limited information on the capacity of different types of compost in reducing aluminum, however, Orozco and Thienhaus (1997) found trends in Al3+ decline and signal the potential of compost to improve this chemical soil indicator. Therefore, pen compost feather performs better compared to traditional compost to reduce aluminum toxicity levels in acidic soils, thus showing its great potential and differentiation with other types of compost.
Conclusions
Significant differences (p <0.05) were found between the treatments applied in levels of organic matter, nitrogen, phosphorus, potassium, aluminum, cation exchange capacity and changeable acids. The pH, calcium, magnesium and available cadmium significant differences for p <0.05.
Treatments showed increases in organic matter, nitrogen, phosphorus, and potassium and decrease acids changeable and interchangeable aluminum; the latter showed a reduction from 5.14 FC1 to 3.34 Cmol. Kg-1 at FC4, reducing by 35.01% on average.
The Feather based compost, at a rate of 4,000 to 6,000 kg. ha-1 showed positive effects similar to traditional compost on chemical indicators that define soil quality, however, it presented comparative advantages in reducing aluminum levels. This result shows feather compost with advantages over compost made with other materials and can be used to improve some fertility indicators and reduce toxic levels of aluminum in acidic soils, typical of the tropics.
Recommendations
To carry out proper management, under the criteria of organic production, it is recommended to:
Improve fertility indicators by applying feather compost, with a maximum ratio of 30% chicken feathers, higher percentages reduce the pH of final compost and can have negative effects on soils and plants.
4 000 kg ha-1 is an adequate amount, higher amounts offer the same benefits and preferably in soils with high levels of aluminum, to reduce the toxic effects on plants.