Iris Publishers - World Journal of Agriculture and Soil Science (WJASS)

Biofertilizer Impacts on Cassava (Manihot Esculenta Crantz) Rhizosphere: Crop Yield and Growth Components, Igbariam, Nigeria

Authored by Ayodele A Otaiku

Introduction

Cassava (Manihot esculenta crantz) is a perennial shrub grown principally for its starchy roots which are used as food, animal feed and as a source of starch. Cassava tends to be grown on the poorer agricultural lands, without irrigation and with limited application of purchased inputs. It is naturally well adapted to these conditions [1]. Nevertheless, the tremendous variation in conditions to Citation: Ayodele A Otaiku, Mmom PC, Ano AO. Growth, Biofertilizer Impacts on Cassava (Manihot Esculenta Crantz) Rhizosphere: Crop Yield and Growth Components, Igbariam, Nigeria - Paper 1. World J Agri & Soil Sci. 3(5): 2019. WJASS.MS.ID.000575. DOI: 10.33552/WJASS.2019.03.000575. Page 2 of 15 which it is subjected means that cassava production technology needs to be adapted to the varying natural conditions, rather than using costly modifications of the environment to suit a particular production system [2]. An understanding of the manner in which the crop responds to varying environmental conditions is an essential component of designing improved low-input technologies like biofertilizer, well adapted to the particular conditions where individual farmers grow their crops. The cassava crop is essentially grown between 300 S and 300 N latitude of the globe. As the crop moves further north or south of the equator the maximum altitude at which it grows and produces will decrease. The crop is generally not found in areas where the mean average temperature is less than about 20 °C, although in areas near the equator where seasonal temperature fluctuations are small it can be found growing in areas with a mean temperature as low as 17 °C [3].

To increase the yield potential of cassava, the crop has been reported to respond to good soil fertility and adequate fertilizer [4]. The major nutrients required by cassava for optimum top growth and tuber yields are nitrogen (N) and potassium (K). Soils that have low N (<0.10% total N) and K (<0.15 meg/100 g) will require an additional fertilizer for optimum tuber yield [5]. Adequate K levels in the soil stimulate the response to N fertilizers, but excess amount of both nutrient leads to luxuriant growth at the expense of tuber formation [6]. Cropping systems influence fertilizer requirements of cassava; for example, the continuous cropping of cassava leads to fast depletion of major nutrients, especially N and K and will require fertilizer supplement to give stable yield. Cassava removes about 55 kg/ha N, 132 kg/ha P and 112 kg/ha K reported by [7].

Cassava Improvement and Biotechnology

However, farmers rarely use chemical fertilizer due to scarcity and cost, hence the dependence on cheap organic sources of nutrients. These reasons necessitate research on increasing effectiveness of organic manures and suitable rate of application. The effect of digester effluent was compared with pig and cattle manure [8] and it was found that bio-digester effluent gave higher biomers, yield and protein content of cassava. These necessitate the biofertilizer research production using agriculture wastes inoculated with broad spectrum microorganism accelerated composed in an anaerobic bio digester. One of the factors responsible for low yield is declining soil fertility. In the past, soil fertility has been sustained through long fallowing [9]. When biofertilizers applied as soil inoculants, they multiply and participate in nutrient cycling and benefit crop productivity [10]. OBD-Biofertilizer composted using anaerobic bio-digester technology (https://www.youtube.com/ watch? v=Hi_OpgVcFcg biofertilizer) from bio-waste in anaerobic digester inoculated with beneficial microbes that exhibit differing metabolic capabilities.

Biotechnology tools have been adapted to cassava and are currently incorporated in different projects for its genetic improvement. A molecular map has been developed [11,12] and marker-assisted selection is currently used for key traits [13]. Molecular markers that allow selection of segregating progenies that carry the resistance of Cassava Mosaic Disease (CMD) have been successfully utilized [13]. A molecular genetic map has been developed for cassava [12] where cassava genetic improvement can be made more efficient through the use of easily assayable molecular genetic or DNA markers (MAS) that enable the precise identification of genotype without the confounding effect of the environment; in other words, increasing heritability.

Genetic transformation protocols are available and have been used successfully for the incorporation of different genes [14]. As the crop has evolved and new improved varieties that satisfy the most important needs have been released and adopted by farmers, new challenges and opportunities arise. An important need is to introduce herbicide tolerance in the crop. Several approaches can be taken from genetic transformation [15], to screening for the natural occurrence of tolerance to certain herbicides, to the induction of mutations as already demonstrated for different herbicides and different crops [16]. The lack of genetic variability for overcoming the problem of post-harvest physiological deterioration remains a major bottleneck for cassava utilization and commercialization, although significant breakthroughs have been achieved recently.

Systemic Approach for Sustainable Agriculture Delivering food security and improving food quality to sustain population growth without compromising environmental safety is global benchmark for green revolution [17]. The beneficial effects and mechanisms of microbes on plant health and fitness and their utilization in agriculture are widely studied and documented [18- 23]. The rhizosphere is the interface between roots and the soil where nutrient absorption for plant growth in agroecosystems is facilitated. Carbon flows from the plant to the soil ecosystem as simple organic compounds providing the necessary food basis for the corresponding microbiological processes that are vital for soil ecosystem functioning [24]. Both plant beneficial microorganisms (plant growth promoters and biocontrol agents) and pests (root pathogens and root feeding insects) are common inhabitants of the rhizosphere [25], all affecting C, N and P biogeochemical processes in the soil. Functional traits of the beneficial rhizosphere microbiome in relation to plant nutrition and health include organic matter decomposition, P solubilization and transport, N fixation and biocontrol of root pests [26]. Biological indicators in the past stressed management effects on biodiversity, e.g., were conservation oriented, but recent developments emphasize methods indicating soil functions and general soil health [27-30]. These different approaches reflect the obvious interrelations between physical, chemical and biological agents in the soil systems.

Biofertilizer

A key merit of microorganisms is to assimilate phosphorus for their own requirement, which in turn available as its soluble form in sufficient quantities in soil. Pseudomonas, Bacillus, Micrococcus, Flavobacterium, Fusarium, Sclerotium, Aspergillus and Penicillium have been reported to be active in the solubilization process [31].

A phosphate-solubilizing bacterial strain Micrococcus sp. has polyvalent properties including phosphate solubilization and siderophore production [32]. Similarly, two fungi Aspergillus fumigatus and Aspergillus Niger were isolated from decaying cassava peels were found to convert cassava wastes by the semisolid fermentation technique to phosphate biofertilizers [33] Burkholderia vietnamiensis, stress tolerant bacteria, produces gluconic and 2-ketogluconic acids, which involved in phosphate solubilization. Potassium solubilizing microorganisms (KSM) such as genus Aspergillus, Bacillus and Clostridium are found to be efficient in potassium solubilization in the soil and mobilize in different crops [34]. Mycorrhizal mutualistic symbiosis with plant roots satisfies the plant nutrients demand [35] which leads to the enhancement plant growth and `development and protect plants from pathogens attack and environmental stress Figure 1. Pseudomonas aeruginosa has been shown to withstand biotic and abiotic stresses [31]. Paul and Nair [36] found that P. fluorescens MSP-393 produces osmolytes and salt-stress induced proteins that overcome the negative effects of salt. Microbial inoculants genera in the OBD-Biofertilizer are isolated using the growth media in Table 1 from different agro biowaste and inoculated into the composted biofertilizer (Plant Growth-Promoting Rhizobacteria. Microorganisms, PGPRs) Table 2.

Manipulation of the plant microbiome has great potential in reducing the incidence of pests and diseases [37,38], promoting plant growth and plant fitness, and increasing productivity [39,40]. Single strains or mixed inoculum treatments induced resistance to multiple plant diseases [41]. In recent years, several microbial biofertilizers and inoculants were formulated, produced, marketed, and successfully used by farmers worldwide. Many processes in the rhizosphere lead to interactions been roots, microbes, water, and nutrients. For example, plant roots and microbes compete for nitrogen, and most likely other nutrients. The rhizosphere has been defined in terms of the effects of roots on soil microorganisms, the depletion of water [120], changes in pH [43], adhering soil [44], Hiltner [45] defined the rhizosphere as the soil influenced by roots. The rhizosphere is not a static place, but rather a dynamic system of processes and increasing the spatiotemporal resolution of rhizosphere measurements will lead to new insights and allows it to be considered as an extended phenotype [46], or an external manifestation of a plant’s genetics.

Rationale and Significance

The cultivation of the resistance of Cassava Mosaic Disease (CMD) in response to chemical and biofertilizer using recommended application to study the crop yield and crops components was the object of the research. Planting one stake of cassava per hill or stand using 1m x 1m spacing, by the National Root Crops Research Institute (NRCRI) Umudike, Nigeria, was a major breakthrough in cassavabased farming system practices results to the production of larger roots, high yield per stand and makes other farm operations such as weeding and fertilizer application easy. The reasons advanced for the low adoption was low cassava population, low yield per unit area and weed growth in farms. Therefore, farmers are demanding for an increase in the number of cassavas to be planted per hill or with little or no chemical pesticides applied during cultivation. Cassava yields are compromised by pests such as whiteflies, mites, and weevils, which cause significant crop losses through the spread of viral disease and direct damage to plants which can reduce yields by up to 40% [47]. Studies shows the enhanced by the production of bioactive substances having similar effects as that of growth regulators besides nitrogen fixation through biofertilizer leading to greater dry matter production was reported by Ramanandam et al. [48]. The higher dry matter production is attributed to the cumulative effect of progressive increase in the growth attributes, viz., plant height, stem girth and number of leaves per plant [49]. Cassava is generally weeded by hand (hoe) 2-3 times during the first 3-4 months, but herbicides across the globe, Figure 3. The excitation (biofertilizer application) to the cassava cultivation soil system is functional characteristics of the impacts on rhizosphere considered for diagnostic tests of ‘Biofertilizer rhizosphere holistic soil function’. With the narratives in Figure 2.

Optimizing cocktails of microorganisms inoculated in the biofertilizer production will produce microbial enzymes and metabolites, which mimic the multiplicity of bio-control mechanisms, set-up by microorganisms [50]. This category includes microbial secondary metabolites and hydrolytic enzymes as glucanases, proteases, lipases, and chitinases. These molecules can be used alone or, better, in combination; they can also be exploited in addition to chemical pesticides with the scope to favor their action, thus reducing the introduction and impact of synthetic pesticides on ecosystems. Yadav et al. [51] obtained consistently higher crop yield with NPK fertilizer mixed with organic manure over NPK inorganic fertilizer alone, Ano and Emehute [52] also obtained higher ginger rhizome yield with organic manure mixed with inorganic fertilizer over inorganic fertilizer alone. Complementary use of organic manure and inorganic fertilizer improves the soil resource base. The effect of biofertilizer on cassava microbiome and phytobiome is unknown or under investigation today. This research article series reports results application of accelerated OBD-Biofertilizer applied alone and in combination with inorganic fertilizer NPK (15:15:15).

The objectives of this paper are “biofertilizer rhizosphere diagnostic tests” to directly evaluate the dynamics of soil in response to targeted forcing (application of bio-fertilizer) in cassava cultivation in the tropic (eastern Nigeria). The observable dynamics provide information on the internal pattern of interacting processes of cassava-microbes interaction as an integral function of the impact of soil management and affirmed by Kibblewhite et al. [28] criticize the “reductionist” approach of using simple indicators describing some fixed state of the soil. In recent years, several microbial biofertilizers and inoculants were formulated, produced, marketed, and successfully used by farmers worldwide. The relationship between rhizodeposition and plant nutrient status is highlighted by the rhizosphere priming effect where N mineralization is increased near roots due to microbial activity [53]. The mapping of microbes in soil has identified microbial hotspots in the rhizosphere [54].

Better understanding of interactions between roots and rhizosphere processes promise to lead to new knowledge and mechanistic insights of the ‘functions of rhizosphere microorganisms on cassava crop cultivation and development:

Paper 1: (Biofertilizer impacts on cassava (manihot esculenta crantz) Rhizosphere: Crop yield and Growth components, Igbariam, Nigeria).

Paper 2: (Biofertilizer impacts on cassava (manihot esculenta crantz) rhizosphere: Soil health and Quality, Igbariam, Nigeria).

Paper 3: (Biofertilizer Impacts on Cassava (Manihot Esculenta Crantz) Rhizosphere: Sustainable soil management, Igbariam, Nigeria).

These papers construct was affirmed by similar work of Cheng et al., [55], where the strategy of one organism depended on the strategies of others, demonstrated that rhizosphere priming could develop as a mutualism between plants and microbes in some limited ecological conditions. Such a systemic approach ~ (Figure 3), providing a clear perspective on how soil functions emerge from small-scale process interactions, is a prerequisite to actually understanding the basic controls and to developing science-based strategies towards sustainable soil management [56].

Materials and Method

Anaerobic digestion

During the anaerobic digestion process, organic compounds are broken down, firstly via lactogenic bacteria to methane precursors, largely volatile fatty acids (VFAs) and then to methane and other products via methanogenic bacteria. OBD-Biofertilizer composted using anaerobic bio-digester technology (https://www.youtube. com/watch?v=Hi_OpgVcFcg biofertilizer) from bio-waste in anaerobic digester inoculated with beneficial microbes that exhibit differing metabolic capabilities. Under anaerobic conditions, organic forms of nitrogen (N) are converted into Ammonium-N (NH-N), i.e. readily available nitrogen.

The readily available nitrogen (RAN) content of cattle slurry is typically 50% and pig slurry 60% of Total-N [57]. It might be anticipated that a measurable increase in the proportion of readily available N would occur in these materials, as a result of the digestion process. Propagation of beneficial microbes. The isolated microbe was propagated using enriching non-selective medium (CPMA). The strains of each group were incubated separately for 7 days at 25 °C and then in mixture for 72 hours at 37 °C under agitation at 75 rpm. The bacterial isolates were then subjected to a series Gram staining and colony count [58]. The comparison was made against the database containing identification patterns for Gram positive and Gram-negative bacteria species.

Bio-waste Recycling to Biofertilizer

Agriculture bio-waste materials composted by anaerobic digester (AD) and inoculated with broad spectrum inoculants OTAI AG® (Table 2) and Oso Bio-Degrader (OBD-Plus®) called microbial inoculants. Inoculated beneficial microbe’s direct analysis of metabolites in situ has been achieved for antibiotic lipopeptides from several Bacillus subtilis and for pyrrolnitrin, 2,4-diacetylphloroglucinol and phenazine-1-carboxylic acid from Pseudomonas fluorescens strains. During the anaerobic digestion process (Figure 4, Plates 1&2) available for the biofertilizer production, Abeokuta, Nigeria.

YOU Tube https://www.youtube.com/watch?v=pG2ODAx3ICY. OTAI AG® is PGPR (Table 2) and beneficial microbial inoculate an easy-to-use applied to the biowaste carrier material (composted) biofertilizer production with industrial standardized process of production and similar to the report by Schmidt [31]. Biofertilizers price is not the same as composts and have been tested as growth media for PGPR [31]. PGPR and/or arbuscular mycorrhizal fungi (AMF) [59] combine inoculation often resulted in increased growth and yield, compared to single inoculation through improved nutrient uptake [60] and resultant interaction of bacteria and AM fungi have beneficial functions related to nutrient uptake, particularly when PGPR [61] and N2-fixing bacteria are involved. Survival of the PGPR is important both during the storage period of the bioproduct and after being introduced into the soil for solid carriers, powder or granules. Standard sizes of the powder material may vary from 75 μm to 0.25 mm [62] and application methods depend on the kind of crop concerned can be inoculated by broadcasting the inoculum over the soil surface, alone or together with seeds, or by in-furrow application, seed dressing, or coating; tree crops can be initially inoculated by root dipping or seedling inoculation [63].

Chemical analyses: Total Nitrogen Kjeldahl procedure [64]; Available P Olsen’s method [65]; Available K by Flame photometric method [66]; pH [67]; Electrical Conductivity by Walkley Black method [68]; Micronutrients (Zinc, Iron, Copper, Manganese) ppm Atomic absorption Spectrophotometric method using DTPA (Diethyl Triamine Penta Acetic Acid) by Lindsay and Norvell [69].

The use of mineral fertilizer in combination with poultry manure has shown an increase yield as much as 60 t/ha of cassava roots [68]. The fertilizers supplied the bulk of the macronutrients needed by the plants, while the organic sources provide secondary and micronutrients which are only needed in very small quantities and improve the soil’s physical conditions [86,87] as confirmed in the Table 5 and Figure 4 where treatments with 600 kg/ha NPK 15:15:15 had a yield of 35.6 t/ha and 300 kg/ha NPK 15:15:15 + 3 t/ha OBD-Biofertilizer had a yield of 30 t/ha using Fischer’s least significant difference (F-LSD) at 5% probability due to the impacts of microbial metabolic processes related to Plant nutrition in the biofertilizer .Nutrients contained in organic manures are released more slowly and are stored for a longer time in the soil, thereby ensuring a long residual effect [88]. A combined use will increase synchrony and reduce losses by converting inorganic N into organic forms [89]. The resultant impacts is integrated nutrient management programmed with increase cassava yield through improving soil productivity, higher fertilizer use efficiency, reduces the environmental problems that may arise from the use of sole inorganic fertilizers and improves the microbial properties of the soil and sustain maximum crop productivity and profitability [90]. Endophytes are also of special interest for their high number of microbial niches and environments they may inhabit and provide therefore a high potential as a less exploited resource. A lack of either N or P application to mother plants did not significantly affect the rate of sprouting, whereas a lack of K application reduced it significantly [41].

Impacts of photosynthesis

The C4 plants tend not to light saturate, have low photorespiration, high photosynthetic rates on a per unit leaf area basis and hence are also nitrogen and water use efficient. Cassava has normally been considered to be a typical C3 plant [91,92]. The photosynthetic rates reported by El Sharkawy [93] for cassava in field grown plants (40 μmol CO2/m2/s) are high for a C3 plant. Furthermore, wild species of Manihot have photosynthetic rates as high as 50 μmol CO2/m2/s [93]. Work at CIAT suggested that cassava might be a C3-C4 intermediate [94]. Connor & Palta [95] found that cassava stomata closed in well-watered and stressed plants in the field at midday. Cassava stomata are extremely sensitive to the Vapor Pressure Deficit (VPD) between the leaf and the air [39]. A whole series of trials have shown a relation between photosynthetic rate of individual leaves and the root yield of cassava under stressed and unstressed conditions. El Sharkawy et al. [96] found that photosynthetic rate measured in preliminary yield trials was correlated with root yield in subsequent independent yield trials.

Increased yield associated with increased photosynthetic rate, as expected, increases the nitrogen use efficiency [96], and also, presumably, water use efficiency. Furthermore, recently it has been shown that activity of PEP carboxylase, an enzyme associated with C4 photosynthesis, is correlated with photosynthetic rate and yield. Thus, it might be easier to screen parent materials for crosses for their PEP carboxylase activity in breeding programs. The dry matter content of cassava roots ranges from about 25% to up to 40%. Hence, it is more cost effective to produce high dry matter products [97]. The dry matter content of cassava roots is a varietal characteristic. The drop in dry matter content is probably due to mobilization of starch reserves in the roots to support the flush of new leaves [98]. Consequently, it is not uncommon for stressed plants of vigorous varieties to produce more roots than unstressed plants [95]. Cassava is capable of exploiting the available water to a depth of 2m [99]. In a fairly typical soil, the cassava plant can extract the equivalent of 160 mm of soil water during a drought period [93]. Rather than growing continuously and ending up with low levels of nutrients in plant tissue, the cassava plant tends to reduce its growth according to the available nutrients (Plates 3 & 4). This is particularly true in the case of nitrogen [100] but appears to be less so in the case of phosphorous [101] and potassium. Nevertheless, on extremely low phosphorous soils, well managed to maintain effective strains of mycorrhiza, cassava performs very well [102]. Since nutrient removal is mainly a function of yield, it is more practical to calculate nutrient removal per ton of fresh roots harvested. Howeler [73] at harvest reported only the crop removes mainly K, less N and very little P.

Indexing List of Iris Publishers: https://medium.com/@irispublishers/what-is-the-indexing-list-of-iris-publishers-4ace353e4eee

Iris publishers google scholar citations:

https://scholar.google.co.in/scholar?hl=en&as_sdt=0%2C5&q=irispublishers&btnG=

Search This Blog

Iris Publishers Agriculture Soil Science