General conditions of research
Arbuscular mycorrhizal fungi (AMF) used is a product of MycoGrow with a carrier ingredient in zeolite and contains 33 spores per gram endomycorrhiza, 300 live propagules per gram and 18 kinds of amino acids. The alfisol soil used in this study had 0.18% total N (low), 2.04 ppm available P (very low), 0.11 mol(+)/kg exchangeable K (low), 1.26% organic carbon (low), 19.73 cmol(+)/kg CEC (moderate), 6.5 pH (somewhat acidic) and 8% moisture content. Alfisol has low soil fertility rates, low soil pH, low nutrient content such as N, P, K, organic carbon, Mo, Mg and low soil microbiological content, while high in mass density and erosion sensitivity
(Kaharuddin et al., 2019; Soetedjo et al., 2019).
The results of the analysis of organic manures used in this study (Table 1) show that the pH in manures includes somewhat alkalis if it is in the range of 7.6-8.5 and alkalis if located >8.5. According to
Fan and Li (2014), fertilizer with alkaline pH can increase soil pH significantly and keep soil pH in the range of 7-7.4. The highest organic carbon and CEC content (Table 1) is found in compost fertilizer, 21.92% and 53.79 cmol(+)/kg. Compost fertilizer has a high C/N ratio that can lead to decreased N’s availability, limiting microbial metabolism, resulting in low demand for P microbes and high potential mineralization P
(Chen et al., 2020; Gao et al., 2019).
Plant height
The interaction between organic manures and AMF doses has no significant effect, while organic manure exerts a significant impact on plant height. The dose of AMF in a single way has no significant effect on the plant height. The addition of organic manures might have released nutrients, especially P and limit the formation of symbiosis between AMF and host plants so that the positive effects of AMF are reduced
(Kahiluoto et al., 2000; Kahiluoto et al., 2001; Richardson et al., 2011). Fertilization should be considered when using AMF in increasing plant growth so that nutrient availability does not limit the positive role of AMF for host plants.
Table 2 shows that the addition of goat manure provides the best results than other manures increasing plant height as also reported earlier
(Prasetyo et al., 2018). The analysis of nutrients in manures (Table 1) shows that goat manure contains higher N, P and K content so that the media with this manure application has more nutrient availability in the soil. Sufficient nutrient content can increase the distribution of roots so that the plant access to water sources is deeper and more stable
(Polverigiani et al., 2018).
The lowest average plant height was recorded in banana with the compost application. Plant growth can be hampered by a decrease in NH
4+ and NO
3- due to microbial immobilization. Microbial immobilization occurs due to the use of manures with a high C/N ratio, while manures with low C/N ratios can increase mineralization
(Baruah et al., 2016).
Pseudo-stem diameter
Banana pseudo-stems form from piles of leaves that sit tightly and regularly to stand upright like plant stems. The interaction between organic manures and AMF doses has no significant effect. In contrast, the treatment of a single type of organic manure had significant impact on the banana pseudo-stem diameter. The AMF dose in a single way has no significant effect on the diameter of the pseudo-stem. This could be due to the moderate to high P in all treatments because of the application of organic manures that suppress the development of AMF in the soil and reduce AMF colonization with roots
(Johnson et al., 2013).
Table 3 shows that the goat manure application to the planting media results in a higher pseudo-stem diameter due to the chemical composition of the goat manure itself (
Sebetha and Mashele, 2019). The high nitrogen content in goat manure forms nucleic acids, amino acids, proteins and cell enlargement so that the diameter of the stem increases
(Purbajanti et al., 2016). The lowest pseudo-stem diameter is seen in the compost application. This might be due to the C/N ratio, which is still high 28.47 (immature) (Table 1). Immature compost will inhibit plant growth because the manure is contaminated with intermediate compounds (such as ammonia and organic acids) toxic to plants
(Liu et al., 2020; Phibunwatthanawong and Riddech, 2019).
Number of leaves
The interaction between the type of organic manure and the dose of AMF, also did not have a significant effect on the number of leaves.
Table 4 shows that the number of banana leaves are in the same range of about 6-7 pieces in all treatments. This is presumably because the N in the organic manures is in the same range 0.7-0.9%. N supply increases chlorophyll content, total protein, sugar content, protein, fat, auxin formation stimulant to soften the cell walls, improve plant ability in absorbing water and metabolites associated with photosynthesis
(Bassi et al., 2018; Dawiyah et al., 2018; Permana et al., 2018; Riyana et al., 2018; Yunus et al., 2018). Leaves that get a sufficient supply of N will form wider strands of leaves with higher chlorophyll to produce high amounts of carbohydrates to support plants’ vegetative growth, including the number of leaves.
Leaf length
The interaction between the type of organic manure and the AMF dose significantly affects the banana leaf length.
Table 5 shows that the most massive leaf length is found in banana with the application of goat manure without AMF, which is 29.65 cm, not significantly different from the 10 g dose and substantially different from the 5 and 15 g doses. This indicates that the length of the banana leaf can grow better if not combined with AMF. Organic manures increases the nutrients available in the soil, especially P.
Smith et al., (2009) explained that when AMF infects the roots, plants expect AMF to distribute nutrients to reduce roots from direct nutrient uptake. AMF cannot provide nutrients due to its limitations, so plant growth is hampered.
Leaf width
The results of the analysis showed that there was an interaction between organic manure types and AMF doses. The interaction that occurs shows that applying organic manure in the planting media has a meaningful relationship with the AMF, affecting the width of banana leaf.
Table 6 shows that the application of cow manure and vermicompost combined with AMF 0-15 g did not result in significantly different leaf widths of banana leaves. These results are in line with the findings of
Begum et al., (2019) who reported that the addition of organic matter combined with AMF shows no significant different results because AMF effectively absorbs nutrients in low soil nutrient conditions.
Mycorrhizal infections
The use of mycorrhiza can increase microbes in the soil and increase the root branches so that the spread of roots is wider
(Samanhudi et al., 2017b; Samanhudi et al., 2017c).
Table 7 shows that the roots of banana plants without AMF treatment appear to be infected with mycorrhiza in the range of 12-24%. Infections that occur in roots without AMF are caused by the absence of
indigenous AMF from the planting media. Based on the observation, it can be seen that AMF infects the roots of banana in all treatments but does not significantly affect on all of the observed variables. This may be because the application of AMF has no significant effect on the vegetative period of banana. AMF helps plants absorb the application of AMF does not significantly affect the parameters of banana growth but could affect the time out of the heart/blossom and fruit weight per bunch.
