The deployment of soluble fertilizers has been one of the most commonly applied agricultural practices in the bid to increase crop yield. However, the production of soluble fertilizers has a considerable economic cost and consumes a substantial amount of energy. In general, soil organic matter provides the nutrients needed for plant growth in organic agriculture.However, these nutrients are not sufficient if the best yield is to be obtained. The aim of our field experiment was to evaluate the effectiveness of phosphate and potassic sources (rocks, biofertilizers and soluble fertilizers) based on several sugarcane characteristics and soil attributes.Our experiment was conducted over two consecutive years, and we assessed the effect of using sugarcane filter mud cake (SFMC). In addition, we mixed the phosphate and potassic sources with earthworm compost enriched in N by inoculation with diazotrophic bacteria (OM) and applied at 50, 100 and 150 % of the recommended dosage rate (RDR). The PK biofertilizer with OM enriched in N positively affected sugarcane height, yield, and industrial characteristics. The application of SFMC greatly increased available P and K in the soil and plant characteristics with residual effect in the two consecutive harvests. We conclude that the biofertilizer has the potential to increase sugarcane characteristics and may represent an alternative to soluble fertilizers.Keywords: Acidithiobacillus, organic fertilization, organic matter, soil nutrients, sulfur oxidation with organic matter has been reported in experiments using annual plants, such as cowpea (Stamford et al., 2008(Stamford et al., , 2011 and melon (Oliveira et al., 2014), grown in both acidic and alkaline soils.The goal of this study was to evaluate the effectiveness of biofertilizer produced from P and K rocks with elemental sulfur inoculated with Acidithiobacillus bacteria and with earthworm compost. In addition, we tested the use of sugarcane filter mud cake (SFMC) to provide nutrients for plant growth and to neutralize the acidity of the PK rock biofertilizer. The PK sources (rocks and biofertilizers) applied at different dosage rates were compared with soluble fertilizers, and their effects on the growth and industrial characteristics of sugarcane and several soil attributes were assessed based on two consecutive crop seasons. Materials and MethodsA field experiment was conducted on a sugarcane field located in Goiana, Pernambuco, Brazil (07° 33' S and 35° 00' W; altitude 13 m). A sandy loam soil, representative of the Typic Fragiudult from the tableland rainforest region with low available P and K levels, was used.

ABSTRACT. The production of biofertilizers from rocks increases nutrients for plant nutrition without environmental pollution. The aim of this study was to evaluate the effectiveness of biofertilizers from phosphate and potassium rocks mixed with organic matter (earthworm compound) inoculated with free living diazotrophic bacteria (NFB 10001) and Cunninghamella elegans (fungus with chitosan) on yield, characteristics, and nutrient uptake of banana (cv. Williams), and attributes of a Red Yellow Argisoil of the rainforest Zone of Pernambuco, Brazil. The experimental design included two biofertilizers: (a) PK rock biofertilizers plus organic matter (NPKB) and (b) bioprotector (NPKP) applied at 50, 100 and 150% of the recommended rate for banana, which were compared with soluble mineral fertilizers (NPKF) applied at the recommended rate, and earthworm compound (20 ton ha -1 ). The best results of the plant parameters were obtained with NPKB and NPKP applied at the highest rates (150% RR). A normal yield was produced when NPKB and NPKP were applied at the highest rates and NPKF at the recommended rate. The available P and K in the soil showed a significant fertilization effect, especially when NPKB and NPKP were applied at the highest rates. The biofertilizer and bioprotector may be alternatives to mineral soluble fertilizers.

To improve yield and nutrient absorption, the addition of fertilizers to provide nutrients in adequate quantities is recommended. An alternative substitution for soluble fertilizer is the use of Acidithiobacillus bacteria to produce rock biofertilizer that is then mixed with organic matter inoculated with diazotrophic bacteria (Beijerinckia indica) for N enrichment. This study evaluates the effectiveness of biofertilizer on nutrient uptake and its interaction with sugarcane filter cake in field-grown sugarcane on an Ultisol in the Brazilian rainforest region. The experiment used two NPK fertilizer treatments (biofertilizer and soluble fertilizer) applied at three rates (50, 100 and 150% of the recommended rate [RR]) and a control treatment of earthworm compost (20 t ha -1 ). The fertilizer treatments were applied with and without filter cake, in four replicates. Total C and N, available P and K, and exchangeable Ca and Mg in plants (upper shoots, leaves and stems) as well as soil samples were analyzed.The biofertilizer showed similar responses as did the soluble fertilizer in nutrient uptake in the different parts of sugarcane and in the soil samples. The effects of biofertilizer were enhanced by the interaction of the fertilizer treatments with sugarcane filter cake. We concluded that the biofertilizer enriched in N by inoculation with B.indica may be a viable alternative for the replacement of soluble fertilizers in sugarcane.

No abstract

Fertilization is one of the most important means to improve plant production and nutrient uptake. Tomatoes plants are very exigent on fertilizers and sensitive to diseases. For satisfactory yield and fruit quality soil fertility and diseases need to be controlled. The aim of this paper was to evaluate the effectiveness of a bioprotector that contains fungi chitosan as an alternative biofertilizer, which releases nutrients and induces resistance against tomatoes wilt by Ralstonia solanacearum bacteria. The treatments were: 1-soluble NPK fertilizers (NPKF) in recommended rate (RR), 2-bioprotector (NPKP) with fungi chitosan in half of recommended rate (50% RR), 3-NPKP 100% RR, and 4-NPKP 150% RR. Treatments without bacterial inoculation (PO) and with bacterial inoculation (P1) were added to evaluate the plant characteristics (plant height, shoot diameter, number of leaves in ramification, fresh and dry matter of shoots). The symptom classes used to observe the induction of resistance were: (--) plants with no disease symptoms; (-) plant with slight symptoms; (+) plants with drastic symptoms and (++) plants died. Plants receiving the soluble fertilizers (NPKF) showed drastic disease symptoms one week after R. solanacearum inoculation, and all the plants died two weeks after inoculation. Plants with NPKP that contains Cunninghamella elegans in rates 50, 100 and 150% RR induced resistance for bacterial disease and promote better plant characteristics. The results showed that the bioprotector displays normal characteristics. The protector may be used as alternative for conventional fertilizers, especially inducing resistance for bacterial control.

Organic matter has low N content; however, organic matter may be enriched by inoculation with selected diazotrophic bacteria. The aim of the paper was to evaluate the effects of biofertilizer produced by mixing different types and proportions of organic matter inoculated with the diazotrophic bacteria Beijerinckia indica. The experiment consisted of plastic trays (6 L) containing 5 kg of three different types of organic matter (filter mud cake, earthworm compost, and crop residue) applied in the following proportions (v:v:v

The production of biofertilizers from rocks is an economic process that increases nutrients for plant nutrition and reduces environmental pollution. The aim of the study was to evaluate the effectiveness of the bioprotector from phosphate and potassium rocks mixed with an earthworm compound inoculated with free-living diazotrophic bacteria (Beijerinckia indica) and fungus containing chitosan (Cunninghamella elegans) on the characteristics of tomatoes, peppers and green peppers inoculated and noninoculated with the wilt bacteria Ralstonia solanacearum. The fertilization treatments were: bioprotector applied at the 50% recommended rate -RR (NPKP 50 ), 100% RR (NPKP 100 ) and 150% RR (NPKP 150 ); soluble fertilizers applied alone at the recommended rate RR (NPKF 100 ), with antibiotic (NPKF 100 +ant) and with crustaceous chitosan (NPKF 100 +C). A control treatment with earthworm compound (20 t ha -1 ) was used for comparative purposes. The best results for all horticultural plants were obtained with the bioprotector (NPKP) applied at the highest rate (150% RR) and with the soluble fertilizer (NPKF) at the recommended rate for plants not inoculated with Ralstonia solanacearum. With regard to the effect of the bioprotector in the control of Ralstonia solanacearum, a different response for the horticultural crops with peppers revealed normal growth when inoculated with the pathogenic bacteria, and all of the tomato plants with soluble fertilizer alone died after pathogen addition. Soluble fertilizer with the addition of antibiotic and crustaceous chitosan protected green peppers and peppers against R. solanacearum, particularly when using chitosan. The bioprotector (NPKP) appears to be an alternative to soluble fertilizer.

The association between sorghum and N 2fixing bacteria has been assessed only under limited conditions. We investigated biological nitrogen fixation (BNF) in situ in fifteen sorghum genotypes with dry or succulent culm types under five edaphoclimatic conditions. One randomized block experiment was established in each of five locations, from the humid to the semiarid regions of Pernambuco state, Brazil. BNF was estimated using the 15 N natural abundance method by comparing the average d 15 N value of each sorghum genotype with those of the reference species. High levels of productivity, up to 22 Mg shoot biomass ha -1 in the 3-month cycle, were obtained where rainfall was high, and up to 5 Mg ha -1 was obtained under low rainfall. The nitrogen contents showed a similar pattern as biomass production, and the genotypes with the highest productivity accumulated from 200 to 300 kg N ha -1 . BNF ranged from 55 to 78% of plant N in one location and from 36 to 56% in another location, but BNF did not occur in the other three locations. Although the factors that blocked effective symbiosis were not determined, symbiosis was not influenced by P or K availability. The proportion of N 2 fixation was similar in the grainproducing, dry culm genotypes and in the sugar-rich, succulent culm genotypes. The sorghum genotypes fixed N 2 , reaching up to 218 kg ha -1 N, without inoculation with diazotrophs. Therefore, sorghum has a high potential to fix atmospheric N 2 , but the factors that block N 2 fixation must be identified for crop management planning.