Ha-1 Of Manure Research Articles

Effect of exopolysaccharide-producing Azotobacter and cow manure on nutrient uptake and root-to-shoot ratio of sorghum

Nitrogen-fixing Azotobacter synthesizes exopolysaccharide, which is important among other to improve aggregate stability and hence nutrients uptake. A pot experiment has been conducted to determine the effect of exopolysaccharide-producing Azotobacter and organic matter on nitrogen, phosphor, and potassium uptake by the shoot of sorghum (Sorghum bicolor (L.) Moench), and plant growth. The pot experiment was setup in randomized block design which test eight combination treatments of Azotobacter isolates (AS5, AS6, and AS5 + AS6) and organic matter application (with and without 20 t ha-1 of cow manure). The result showed dual inoculation of Azotobacter AS5 and AS6 inoculation combined with cow manure application increased N and P uptake. The dual inoculation treatment did not affect root length; but increased the shoot height and dry weight when accompanied by the application of cow manure. The ratio of root and shoot dry weight was not influenced by single or dual Azotobacter inoculation with or without organic matter.

Comparative Effects of Sole and Combined Application of Manure and Inorganic Fertilizer on Growth and Yield of Sweet Corn in Maiduguri, Nigeria

A field experiment was conducted at the Teaching and Research Farm of Ramat Polytechnic Maiduguri, Borno state, Nigeria. to determine the comparative effects of manure and organic fertilizer on growth and yield of sweet corn. The experiment consisted of four treatments 0 kg ha1, 120 kg ha-1 manure, 120 kg ha-1 inorganic fertilizer and 60 kg ha-1 manure + 60 kg ha-1 inorganic fertilizer. The treatments were laid in a complete randomized block design (RCBD) with three replicates. At 6 and 8 WAS a combination of 60 kg ha-1 manure 60 kg ha-1 inorganic fertilizer produced significantly taller plants than 120 kg ha-1 manure and 120 kg ha-1 inorganic fertilizer. At 10 WAS 120 kg ha-1 inorganic fertilizer produced significantly taller plants than 120 kg ha-1 manure and 0 kg ha-1. Combination of 60 kg ha-1 manure + 60 kg ha-1 inorganic fertilizer recorded highest grain yield than control 0 kg ha-1 single manure 120 kg ha-1 and 120 kg ha-1 inorganic fertilizer.

Earthworm populations are stable in temperate agricultural soils receiving wood-based biochar

The application of decomposable organic residues such as manure and crop litter is generally beneficial to earthworms. There is an emerging interest in applying biochar, a carbonaceous product of pyrolysis, to temperate agricultural soils. The slow decomposition rate of biochar, which also contains ash and combustion byproducts, could be detrimental to earthworms. The objective of this study was to describe the earthworm populations in biochar-amended soils on a dairy farm in the St. Francis River watershed, Quebec, Canada. Earthworms were collected from replicated field plots under cereal production. Site A received three wood-based biochar types at two application rates (5 and 10 t ha-1 biochar) plus an unamended control, while Site B received wood-based biochar (7.5 t ha-1 biochar), dairy cattle slurry (10 t ha-1 manure), or a combination of the biochar and manure rates plus an unamended control. Earthworms were collected by hand sorting and formaldehyde expulsion from soil pits. Three species, Aporrectodea turgida, Aporrectodea tuberculata, and Lumbricus rubellus, were found at the sites, and Aporrectodea was the dominant genus. Biochar sources, rates, and application with dairy slurry did not affect the earthworm population, which had 52–218 individuals m-2 in 2010 and 4–96 individuals m-2 in 2011. The seasonal variation in earthworm population may be due to flooding in the spring of 2011, which apparently interfered with earthworm reproduction. The similarity in earthworm abundance and biomass in plots with and without wood-based biochar leads to the conclusion that earthworm populations are stable in biochar-amended soils in this cold, humid temperate region.

Photosynthetic Performance, Nutrition and Growth of Campomanesia xanthocarpa O. Berg. in Chicken Manure Substrate and Liming

The aim was to evaluate the effect of chicken manure and substrate liming in the Campomanesia xanthocarpa (‘gabiroba’) physiology, nutrition and growth. Five dosages of chicken manure (0; 5; 10; 15 and 20 Mg ha-1) were studied without and with substrate liming. The treatments were arranged in a 5 x 2 factorial scheme, in a randomized block design with four replications. There was an improvement on the chemical attributes in the substrate and nutrients contained in the plants where liming was performed. The highest plant height of C. xanthocarpa occurred with liming and 9.03 Mg ha-1 of chicken manure. The diameters were liming-grown plants and 4.57 mm with 5 Mg ha-1 of chicken manure. The photochemical efficiencies of PSII occurred in plants grown on liming substrate. It was concluded that C. xanthocarpa plants had their development optimizes with substrate liming and incorporation of 5 Mg ha-1 chicken manure.

INFLUENCE OF FARMYARD MANURE TYPE AND RATE ON TOMATO FRUIT YIELD AND ITS ATTRIBUTES UNDER DRIP IRRIGATION CONDITIONS

A field experiment was conducted at the Agriculture faculty farm of Sebha University, Sebha, Libya, during the winter season of 2017 to assess the impact of different rates of two farmyard manure (FYM) on the yield under drip irrigation. The two types of FYM were poultry and sheep manures at rates of 0, 20, and 30 tons h-1 were mixed with the soil before transplant versus the control. The results indicated that the fresh and dry weights, plant height, number and weight of fruits were significantly affected by different types and levels of FMY. The maximum values of the above mentioned traits were obtained using 30 tons ha-1 of sheep manure compared to the other treatments.

Rendimiento y calidad de forraje de tres cultivos de secano en camas a cuatro y seis hileras con diferentes métodos de fertilización

Introduction: In the temperate-semiarid region of Aguascalientes, Mexico, most of the rural population depends on rainfed agriculture related to the family milk production system. Objective: To evaluate the effect of different fertilization practices on forage yield and quality of three rainfed crops in four- and six-row seedbeds. Methodology: Five fertilization treatments were evaluated: T1) control (no fertilization), T2) chemical fertilization (40-40-00 kg·ha-1 of N-P-K), T3) mixture (28-40-00 kg·ha-1 and 26 kg of zeolite), T4) organic fertilizer (5 t·ha-1 of bovine manure) and T5) mycorrhiza (inoculation with 350 g·ha-1 of mycorrhizal substrate). Maize and sunflowers were planted in four rows, and sorghum in six rows. A randomized complete block design with four replicates was used. Results: Dry matter yield in relation to the control, in T2, T3 and T4 was 100, 84 and 26 % for maize, 123, 177 and 67 % for sunflowers, and 52, 49 and 91 % for sorghum, respectively. T5 was higher compared to T1, but without statistical difference. Forage quality of the three crops showed no increase, except for crude protein in T2 and T3. Limitations of the study: Results correspond to a single cycle (spring-summer). Originality: Good agronomic practices for forage production were established. Conclusions: Agronomic practices (minimum tillage, in situ rainwater harvesting, sowing methods and fertilization) generate a positive effect on yield and forage quality in rainfed crops.

Effect of organic manures and bio-fertilizers on growth and yield of French bean under high altitude rain fed climatic conditions of Gurez-Jammu and Kashmir

A field experiment was conducted at experimental farm of Mountain Agriculture Research and Extension Station Gurez, SKUAST-K (J&K) with five treatments comprising (control, Sheep manure@20 t ha-1,FYM @ 24 t ha-1,Vermi-Compost @ 8 t ha-1 and sheep manure 5t+FYM 6t+vermi-compost 2t+Rhizobium2.5kgha-1during kharif -2019 to find out the response of different sources of organic manures and bio-fertilizers on growth and yield parameters of french bean under high altitude rain fed climatic conditions. Among the treatments studied, significantly highest plant height (57.33 cm), No. of pods plant-1 (38.33), pod yield plant-1 (240.00 g), pod yield plot-1 14.40 kg and pod yield 319.99 q hectare-1 were noticed with the integrated application of organic manures and bio-fertilizer (sheep manure 5t + FYM 6t + vermi-compost 2t+Rhizobium 2.5 kg ha-1).

Effect of Integrated Nutrient Management in Mustard (Brassica juncea L.)

An experiment was carried out during the Rabi season of 2017-18 and 2018-19 on the farmer’s field of Village Bisrekhi, Block Ghorawal of Sonbhadra UP, India to evaluate the effect of different combination of integrated nutrient management in Mustard [Brassica juncea (L.)]. There were 8 treatments namely; T1–control, T2-100% R.D.F., T3-75% R.D.F. + 5t FYM ha-1, T4-75% R.D.F. + 5t poultry manure ha -1, T5 - 75% R.D.F. + 250 kg gypsum ha-1, T6 -75% R.D.F. + 10t FYM-1, T7 -75% R.D.F. + 10t FYM ha-1+ 5t Poultry manure ha-1 and T8 was 50% R.D.F+10t FYM ha-1+5t Poultry manure ha-1+250 kg gypsum ha-1 which were tested in randomized block design with four replications. The seed yield of mustard was significantly increased due to increase the supply of plant nutrients through organic and inorganic sources of plant nutrients. The highest seed yield of mustard was (18.65 q ha-1 ) recorded when applied of 50% R.D.F. + 10t FYM ha-1+ 5 t poultry manure ha-1 +250 Kg gypsum ha-1 (T8) followed by (18.15 q ha-1) with application of 75% R.D.F. + 10t FYM ha-1+ 5t poultry manure ha-1 (T7), however, minimum seed yield mustard crop (15.35 q ha-1) was noted under control plot (T1). The significantly highest oil yield of mustard crop was (6.79 q ha-1) recorded under the application of 50% R.D.F. +10t FYM ha-1+5t poultry manure ha-1 +250 Kg gypsum ha-1 (T8) followed by (6.37 q ha-1) with application of 75% R.D.F. + 10t FYM ha-1+ 5t poultry manure ha-1 (T7), however, lowest oil yield of mustard crop was (4.76 q ha-1) noted under control plot (T1).

Impact of lime and NPK fertilizers on yield and quality of oats on pseudogley soil and their valorisation

In order to determine the effect of fertilization, environment, and their interactions on the yield and oats yield components. Five fertilization treatments (T1-control, T2-80 kg N ha-1, T3-120 kg N ha-1, 80 kg P2O5 ha-1 and 80 kg K2O ha-1, T4-N120P80K80 + 5 t ha-1 of lime and T5-N120P80K80 + 5 t ha-1 of lime + 30 t ha-1 of farmyard manure) were examined during three growing seasons in Kraljevo location in Western Serbia. Grain yield (GY), 1000 grain weight (TGW), hectolitre weight (HW), plant height (PH), panicle length (PL), number of grains per panicle (NGP) and protein content (PC) were analysed. The aim of the study was to determine the effect of organic and mineral fertilization and calcification on the yield and oats yield components. On average, for all fertilizer variants, during the three-year trial, the highest yield of oats 3802 kg ha-1 was obtained in the fertilizer variant with the combined application of NPK fertilizers, lime and manure. Positive highly significant correlation, during in the study trial were found between yields with PH, PL and NGP. Negative and highly significant dependencies were found between protein content with GY, PH and NGP. The results of these studies indicate the importance of rational introduction of adequate quantities of fertilization, calcification and humization in order to make oats as profitable as possible in the agro-ecological conditions in Pannonian Environments.

Integrated Usage of Farm Yard Manure and Urea Improves Wheat Yield and Soil Properties

Optimum usage of fertilizers is an important factor that defines the fate of crop yield by confirming the accessibility of nutrients in soil. Imbalance use of fertilizer not only reduces the crop productivity but also adversely affects the soil properties. A one-year experiment was carried out to explore the impact of different levels of farm yard manure and urea on soil properties, growth and yield of wheat crop. Treatments were application of nitrogen at i) 125 kg ha-1 from urea, ii) 80 kg ha-1 of nitrogen from urea + 10 tons of farm yard manure ha-1 and iii) 20 tons of farm yard manure ha-1. Wheat cultivar Sehar-2006 was used in the experiment. All the treatments’ combination affected crop growth, economic yield and soil properties. However, maximum positive impact of combined use of farm yard manure and urea was observed. Results indicated that productive tillers per unit area (16%), plant height, number of spikelets per spike (12.5%) and economical yield (11%) were greatly enhanced by combined usage of urea and farm yard manure as compared to sole application of urea. Combined application of urea and farm yard manure also positively affected the soil bulk density, particle density, percent porosity and soil saturated hydraulic conductivity as compared to either sole use of urea or farm yard manure. Combined usage of farm yard manure and urea are suggested better to produce higher economical yield along with improved soil properties.

Integrated Usage of Farm Yard Manure and Urea Improves Wheat Yield and Soil Properties

Optimum usage of fertilizers is an important factor that defines the fate of crop yield by confirming the accessibility of nutrients in soil. Imbalance use of fertilizer not only reduces the crop productivity but also adversely affects the soil properties. A one-year experiment was carried out to explore the impact of different levels of farm yard manure and urea on soil properties, growth and yield of wheat crop. Treatments were application of nitrogen at i) 125 kg ha-1 from urea, ii) 80 kg ha-1 of nitrogen from urea + 10 tons of farm yard manure ha-1 and iii) 20 tons of farm yard manure ha-1. Wheat cultivar Sehar-2006 was used in the experiment. All the treatments’ combination affected crop growth, economic yield and soil properties. However, maximum positive impact of combined use of farm yard manure and urea was observed. Results indicated that productive tillers per unit area (16%), plant height, number of spikelets per spike (12.5%) and economical yield (11%) were greatly enhanced by combined usage of urea and farm yard manure as compared to sole application of urea. Combined application of urea and farm yard manure also positively affected the soil bulk density, particle density, percent porosity and soil saturated hydraulic conductivity as compared to either sole use of urea or farm yard manure. Combined usage of farm yard manure and urea are suggested better to produce higher economical yield along with improved soil properties.

Effect of sugarcane bagasse ash and manure amendments on selected soil properties in Western Kenya

This research determined the effects of incorporating sugarcane bagasse ash and cattle manure on soil pH, available P, and cation exchange capacity (CEC) during a 2 seasons’ field experiment in Kakamega County of Western Kenya. The experiment used a Randomized Complete Block Design, 3 replications, and a 3 × 3 factorial arrangement of treatments. Sugarcane bagasse ash and cattle manure application showed highly significant effects on soil properties at P≤0.01. The combined application of 5 t ha-1 sugarcane bagasse ash with 5 t ha-1 cattle manure raised soil pH by 0.18, and with 10 t ha-1 manure by 0.17. These increments were higher than the positive control (2 t ha-1 lime alone), that raised soil pH by 0.03, while negative control (no amendment) decreased soil pH by 0.01 at the end of the 2nd season. Soil available P increased by 6 ppm due to 5 t ha-1 cattle manure and by 4 ppm due to 5 t ha-1 sugarcane bagasse ash. Soil CEC increased due to high application rates of cattle manure at the end of the second season. This study concluded that, the incorporation of sugarcane bagasse ash and cattle manure increased soil pH, available P and CEC. Key words: Available P, bagasse ash, cation exchange capacity (CEC), cattle manure, soil pH, Western Kenya.

Impact of surface soil manuring on particulate carbon fractions in relevant to nutrient stoichiometry in a Mollisol profile

Organic matter application significantly influences soil carbon storage and sequestration in cropland. The investigation of C sequestration through soil organic carbon (SOC) fractions in the soil profile and its relation to nutrient stoichiometry are essential for evaluating the effect of farming practice on soil fertility. This study aimed to examine the effect of cattle manure application on nutrient stoichiometry, which would be associated with soil C stock in SOC fractions, such as microbial biomass C (MBC), dissolved organic C (DOC) and water-soluble organic C (WSOC), coarse particulate organic carbon (cPOC), fine particulate organic carbon (fPOC) and the mineral-associated organic carbon (MOC). A four-year manure application experiment was conducted in a Mollisol, in which fertilization treatments comprised (1) NoF: the non-fertilizer control, (2) F: synthetic fertilizer, i.e. 20.3, 21.2 and 12.2 kg ha−1 of nitrogen (N), phosphorus (P) and potassium (K) in soybean, and 69.0, 28.1 and 6.1 kg ha−1 of N, P and K for corn on an annual basis, respectively, (3) F + M: synthetic fertilizer plus 15 Mg ha-1 of cattle manure and (4) F + 2M: synthetic fertilizer plus 30 Mg ha−1 of cattle manure in a soybean-corn rotation. SOC concentration in top 10 cm of soil was 18 % and 19 % higher under F + M than that under NoF and F, respectively. Whereas, F+2 M significantly increased SOC concentration by 32 %, 32 %, 14 %, and 11 % in 0−10, 10−20, 20−30, and 30−40 cm of soil depth compared to that in respective soil depth under NoF. Compared to NoF and F, manure application (F + M and F+2 M) significantly increased MBC in the top 30 cm of soil depth and DOC concentration in the top 20 cm of soil depth, but significantly decreased WSOC concentration in the top 20 cm of soil depth. F+2 M significantly increased cPOC concentration in the top 30 cm of soil depth compared to NoF and F. F + M significantly increased fPOC concentration in the top 50 cm of soil depth, compared to NoF, and F. F+2 M further increased the fPOC concentration in the top 30 cm of soil depth, compared to F + M. There was no difference among fertilization treatments in MOC concentration in any soil depth. There were significant exponential correlations of C concentration in POC fractions with soil N, P and N/P ratio. These results indicate that the combination of manure and synthetic fertilizer increased C accumulation in the POC fraction especially in the top 30 cm of soil depth. The change of nutrient stoichiometry was responsible to the accumulation of soil organic matter, highlighting that N, rather than P mainly regulated C accumulation in POC. Increasing input of N fertilizer combined with manure application would benefit the formation of soil organic matter in agricultural Mollisols.

EFFECT OF GREEN MANURING WITH MERREMIA AEGYPTIA ON AGRO-ECONOMIC EFFICIENCY OF RADISH PRODUCTION

ABSTRACT The introduction of new crops in northeastern Brazil, associated with the use of the green manure, can become an alternative for family farmers. Thus, the objective of this work was to determine the effect of green manuring with M. aegyptia L. on the agro-economic efficiency of radish production. The experimental design was a randomised complete block with four treatments and five replicates; the treatments were composed of four doses of M. aegyptia (20, 35, 50 and 65 t ha-1 on a dry basis) incorporated into the soil in three cropping periods. In radish plants, we evaluated plant height, fresh and dry mass of shoots, total and commercial productivity of roots, productivity of scrap roots, dry mass of roots and root diameter. The economic indicators gross income, net income, rate of return and profit margin were used to evaluate the agro-economic efficiency of the system. The maximum agronomic efficiency was reached with a commercial root productivity of 7.86 t ha-1 and the addition of 49.29 t ha-1 of green manure. The maximum economic efficiency was obtained with a net income of 11,955.46 R$ ha-1 when a green manure dose of 46.00 t ha-1 was added. The use of M. aegyptia as green manure is economically viable in the production of radish in the semi-arid region of Northeast Brazil.

Effect of Organic Fertilizer and Irrigation Intervals on the Yield and Quality of Cherry Tomato (Solanum lycopersicon var. cerasiforme)

To investigate the effects of organic fertilizers and irrigation frequencies on yield and quality of cherry tomato an experiment was conducted using six fertilizer doses including control (no fertilizer), NPK fertilizer (urea at 300 kg, TSP 200 kg and MoP 250 kg), cow-dung at 5 t ha-1, cow-dung at 10 t ha-1, poultry manure at 5 t ha-1 and poultry manure at 10 t ha-1 with two levels of irrigation frequencies including alternate day irrigation and two day interval irrigation in a split plot design with three replications. Data on yield and quality attributes of cherry tomato like plant height, number of fruits per plant, fruit yield per plant (g), yield (t ha-1), TSS (%) and vitamin C contents (mg 100 g-1) were recorded. Results revealed that poultry manure had significant effects on the yield and quality of cherry tomato. Among the fertilizer treatments, poultry manure at 5 t ha-1 showed the best results on yield and quality of cherry tomato. On the other hand, cherry tomato showed best performance in relation to yield and quality when field was irrigated in one-day interval. It can be concluded that application of poultry litter at 5 t ha-1 in combination with one day interval result in highest yield and quality on cherry tomato.

Chicken Manure and Phosphorus Influence on Biomass Production and Chemical Composition of the Essential Oil of Ocimum kilimandscharicum

The effects of soil incorporation of five rates of semi-decomposed chicken manure (0, 5, 10, 15 and 20 t ha-1), with and without the addition of phosphorus (200 kg P2O5 ha-1) on biomass production and chemical composition of the essential oil from leaves of African blue basil were evaluated. The experimental design was a randomized complete block design in a 5 × 2 factorial scheme, with four replicates. The first cut of plants was performed at 70 days after transplanting (DAT) and the second at 140 DAT. The addition of 20 t ha-1 of chicken manure to the soil induced increase in plants height, fresh and dry mass production and yield of essential oil. The use of chicken manure induced an increase in camphor content and decreased content of 1,8 cineole. After regrowth, biomass production of African blue basil was higher when compared to the first cut.

Adaptation of New Rice High Yielding Varieties on New Constructed Irrigated Rice Field Affected by Sea Water Intrusion in West Tanjung Jabung District, Jambi

Assessment adaptation of several new superior rice varieties on new rice fields affected by seawater intrusion was carried out in Tungkal Ilir Subdistrict, West Tanjung Jabung District, from April to October 2018. The study applied randomized block designs (RBD) with four replications. The treatments consisted of four new rice high yielding varities suitable for tidal/swamps areas namely Inpara 3, Inpara 8, Inpara 9, and Inpari 34 Salin Agritan, and one local rice variety (Londo) as control. Three stems seedlings per clump were planted at the age of 21-25 days, using a 4:1 Legowo planting system. Fertilizer application consisted of basic fertilizer (1.0 Mg ha-1 of lime, 2.5 Mg ha-1 of manure, and 75 kg ha-1 of urea) and supplementary fertilizer (SP-36 150 kg ha-1 and KCl 125 kg ha-1),. Urea supplementation is given based on observations with a leaf color chart (LCC). The results of the study showed that the four new rice HYVs were more adapted as compared to the local rice variety. The performance of the tested new rice HYVs showed quite a good growth appearance and productivity. The highest production was obtained in Inpari 34 Salin Agritan variety 2.85 Mg ha-1, while Inpara 3, Inpara 8, and Inpara 9 ranged between 2.0 and 2.1 Mg ha-1, while the local variety’s productivity was 1.9 Mg ha-1.

English

Niayes and Groundnut basin areas are among the largest strongholds of rainfed agriculture in Senegal. In the agricultural holdings of both agro-ecological areas, main speculations are far from optimizing their agronomic production potential. In order to analyze the organizational capacity and decision-making processes of producers, a global agronomic diagnostic work was undertaken out on the scale of 180 agricultural holdings through socio-economic and technical descriptions, while taking into account endogenous and exogenous factors of the agrarian environment. The results revealed technical and biophysical failures of the resources in their availability and/or use, but also a plethora of constraints which hinder the increase of agricultural activity and the dynamical transition of the unit. These constraints are justified by a precarious technical framework (-15%), a modest size of the agricultural unit (7.45 ha) and a small to medium crop rotation of which 42% of UAA for the first speculation, pearl millet. For the dry cereal, 19% N.P.K phosphate fertilizers use is rated with 26.05 kg ha-1, and 0.46 t ha-1 of background manure for an average yield of 0.59 t ha-1. These conjunctures point to a system of peasant production with low market capital, limited to the satisfaction of family needs. Key words: Family farms, farming practices, pearl millet, Niayes, groundnut basin, Senegal.

Productivity and nutrient export in cowpea fertilized with chicken manure

The analysis of the accumulation and export of nutrients by the cowpea crop is fundamental for a more sustainable fertilization program, because the definition of the doses of organic fertilizers based only on the estimated maximum yield does not guarantee the maintenance of soil fertility. The objective of this study was to evaluate the effect of fertilization with chicken manure on the productivity, accumulation and exportation of nutrients by the pods of cowpea. A randomized block design was used, with five doses of chicken manure (0; 5; 10; 20 and 40 t ha-1) and four repetitions. The highest levels of P and Mg were found in the leaves with the application of 40 t ha-1 of manure. The maximum pod length was 14.47 cm, estimated with the dose of 33.33 t ha-1 of manure. The highest values of diameter, number of pods per plant and pod productivity were observed at the highest dose of manure applied. In relative terms, that is, total exported in relation to the total extracted by the aerial part, phosphorus is the nutrient most exported by the pods, on average 58%, followed by N (55%), K (43%), Mg (40%), S (38%) and Ca (17%). At the highest dose, although Ca accumulation occurred in large quantities (31.3 kg ha-1), only 13% of it was exported by the pods. Fertilizing cowpea with chicken manure supplied essential nutrients and increased pod yield from 7.2 (no fertilization) to 16.3 t ha-1 (fertilization with 40 t ha-1 of chicken manure). The plant remains of the cowpea constitute an important source of nutrients, being obtained at the highest dose of manure applied (40 t ha-1) the following amounts of macronutrients (kg ha-1): N (51.4); P (5.1); K (27.6); Ca (27.1); Mg (8.2); S (5.1), which may return to the soil, with the incorporation of the plants.

Effect of Combined Organic and Inorganic Fertilizer Application on Soil Attributes, Yield and Quality of Sweet Potato (Ipomoea batatas L.)

The use of organic fertilizers in adequate doses is an alternative to reduce the use of inorganic inputs, improving the soil chemical attributes, and increasing the production and quality of sweet potato. In this perspective, the objectives of this study were: (i) to evaluate the effects of fertilization with poultry and bovine manure, Ribumin®, and of conventional fertilization on soil attributes, production, and quality of sweet potato; and (ii) to evaluate the residual effect of organic fertilization on the production components and quality of sweet potato, in the second crop cycle. The two experiments were developed in the 2018/2019 crop year at the Agrotechnical School of the Federal University of Roraima (UFRR), Brazil. The treatments were arranged in a randomized block design with three replications, using a (2 × 5 × 2) + 1 factorial arrangement referring to two manure sources (bovine and poultry manure) and five doses, aiming at increasing the content of soil organic matter (1.35%) to 2.35; 3.35; 4.35, and 5.35%, in the absence and presence of Ribumin®, and an additional treatment referring to organomineral fertilization. For the evaluation of the second cycle, the residual effect of the manure was evaluated by applying only Ribumin® and conventional fertilizers. In the first cycle, the addition of 50.4 t ha-1 of bovine manure without Ribumin® provided the highest values of total (14.7 t ha-1) and marketable yield (14.6 t ha-1). However, the addition of poultry manure associated with the application of Ribumin® provided no increments in the sweet potato production components. Under the same experimental conditions, chemical fertilization can be replaced by fertilization with organic sources.