Residual Effect Of Fertilizer Research Articles

Residual Effects of Pig Slurry Fertilization in a Mediterranean Rainfed Cereal System

An increase in nitrogen (N) use efficiency (NUE) in agriculture is a requirement for sustainable development. The reduction in nitrogen inputs might benefit from the residual N of former organic fertilization procedures. A 10 year experiment was established in a rainfed Mediterranean system (barley–wheat rotation). The objective of this experiment was to quantify the N residual effects of a single pig slurry (PS) application at sowing (20, 40, and 80 m3 ha−1) and up to three years later. The mineral N equivalence method was used to compare the grain yield (GY) and the whole-plant N uptake (WPNU) between the slurry fertilized plots (slurries applied in previous years) and annual mineral N fertilized ones (30, 60, 90, 120, and 150 kg N ha−1). From the total N applied with PS, a fraction of, ca., 21% accounted for the residual equivalent mineral N for a total period of three years after the PS application. For the 20 m3 ha−1 rate, the relative residual N based on the GY and WPNU equaled to 89–90% of the applied organic N, respectively. This rate also allowed for an increase in NUE values to above 33%. In semiarid areas, the introduction of residual N when scheduling fertilization is important to reduce N inputs and to increase NUE.

Residual Effect of Microbial-Inoculated Biochar with Nitrogen on Rice Growth and Salinity Reduction in Paddy Soil.

Increasing soil and water salinity threatens global agriculture, particularly affecting rice. This study investigated the residual effects of microbial biochar and nitrogen fertilizer in mitigating salt stress in paddy soil and regulating the biochemical characteristics of rice plants. Two rice varieties, Shuang Liang You 138 (SLY138), a salt-tolerant, and Jing Liang You 534 (JLY534), a salt-sensitive, were grown under 0.4 ds/m EC (S0) and 6.84 ds/m EC (S1) in a glass house under controlled conditions. Three types of biochar-rice straw biochar (BC), fungal biochar (BF), and bacterial biochar (BB)-were applied alongside two nitrogen (N) fertilizer rates (60 kg ha-1 and 120 kg ha-1) in a previous study. The required salinity levels were maintained in respective pots through the application of saline irrigation water. Results showed that residual effects of microbial biochars (BF and BB) had higher salt mitigation efficiency than sole BC. The combination of BB and N fertilizer (BB + N120) significantly decreased soil pH by 23.45% and Na+ levels by 46.85%, creating a more conducive environment for rice growth by enhancing beneficial microbial abundance and decreasing pathogenic fungi in saline soil. Microbial biochars (BF and BB) positively improved soil properties (physicochemical) and biochemical and physiological properties of plants, ultimately rice growth. SLY138 significantly had a less severe response to salt stress compared to JLY534. The mitigation effects of BB + N120 kg ha-1 were particularly favorable for SLY138. In summary, the combined residual effect of BF and BB with N120 kg ha-1, especially bacterial biochar (BB), played a positive role in alleviating salt stress on rice growth, suggesting its potential utility for enhancing rice yield in paddy fields.

Residual Effects of Compost and Manure Fertilizers on Quinoa Production and Nutrient Uptake

Organic fertilizers have the potential to improve soil quality and quinoa (Chenopodium quinoa Willd.) yields, but their long-standing benefits are unknown. Therefore, a three-years field experiment (2019–2022) was conducted in Morocco to investigate the residual effects of organic fertilizers on the productivity and mineral status of quinoa. Compost and manure were applied during the first season at 5, 10, and 20 t ha− 1 and 10, 20, and 40 t ha− 1, respectively. Soil organic matter (SOM), plant growth, and quinoa yield were monitored during the year of organic fertilizer applications and two and three years after the applications. 40 t ha− 1 of manure produced the highest SOM, plant height, and chlorophyll content index. Compost at 20 t ha− 1 produced the highest grain yield (4.6 t ha− 1) during the first year, but the residual effect of 40 t ha− 1 of manure exceeded other treatments in the second and third years (3.4 t ha− 1 and 1.4 t ha− 1, respectively). Average quinoa grain yield over the three years was highest with 10 and 20 t ha− 1 of compost and 20 and 40 t ha− 1 of manure and average quinoa nutrient content was 1.8 kg N, 0.3 kg P, 4.1 kg K, 0.5 kg Ca, 0.6 kg Mg, 0.5 g Cu, 1.9 g Zn, 7.9 g Mn, and 7.9 g Fe per 100 kg of total biomass. A single application of manure at 20 t ha− 1 was optimal to increase quinoa productivity for three growing seasons, promoting agricultural sustainability in arid regions.

Residual effect of sulphur and boron fertilization as influenced by liming on yield and yield attributes of summer greengram under rapeseed-greengram cropping sequence

Residual effect of sulphur and boron fertilization as influenced by liming on yield and yield attributes of summer greengram under rapeseed-greengram cropping sequence

Efeito residual de fontes de fósforo na presença e ausência de composto orgânico na produção de beterraba e chicória em cultivo sucessivo de brócolis

ABSTRACT The utilization of organic fertilizer for a short cycle crop may allow planting, in sequence, another short cycle crop, without the need for new fertilizers, reducing the costs of a new fertilization. The objective of this study was to evaluate the residual effect of fertilization applied to broccoli with phosphorus sources in the presence and absence of organic compost, on beet and chicory production in subsequent cultivation. In broccoli cultivation, four sources of phosphorus (thermophosphate, natural phosphate, natural reactive phosphate, and triple superphosphate) (600 kg/ha of P2O5) were evaluated in the presence and absence of organic compost (Visafértil®, 55 t/ha) before planting. After the removal of the cultural remains of broccoli, beet and chicory, seedlings were transplanted in the same plots of the first crop treatments. For each species eight treatments were evaluated, in a 4 x 2 factorial scheme. The first factor were the four sources of phosphorus and the second one was the application or not of organic compost before broccoli (hybrid BRO 68) planting. Treatments with organic compost showed greater production of beet and chicory, compared to the absence of compost. Fertilization with organic compost associated to the phosphorus sources provides necessary residual effect to beet and chicory production. The best P source for beet was triple superphosphate, and for chicory, in the absence of organic compost, triple superphosphate was the best source. In the presence of organic compost, the best sources were triple superphosphate and natural phosphate.

Sustaining rice productivity through weather-resilient agricultural practices.

Enhancing productivity and profitability and reducing climatic risk are the major challenges for sustaining rice production. Extreme weather can have significant and varied effects on crops, influencing agricultural productivity, crop yields and food security. In this study, a comparative evaluation of two crop management systems was performed involving farmers adopting a weather forecast-based advisory service (WFBAS) and usual farmers' practice (FP). WFBAS crop management followed the generated weather forecast-based advice whereas the control farmers (FP) did not receive any weather forecast-based advice, rather following their usual rice cultivation practices. The results of the experiments revealed that WFBAS farmers had a significant yield advantage over FP farmers. With the WFBAS technology, the farmers used inputs judiciously, utilized the benefit of favorable weather and minimized the risk resulting from extreme weather events. As a result, besides the yield enhancement, WFBAS provided a scope to protect the environment with the minimum residual effect of fertilizer and pesticides. It also reduced the pressure on groundwater by ensuring efficient water management. Finally, the farmers benefited from higher income through yield enhancement, reduction of the costs of production and reduction of risk. A successful and extensive implementation of WFBAS in the rice production system would assist Bangladesh in achieving Sustainable Development Goal 2.4, which focuses on rice productivity and profitability of farmers as well as long-term food security of the country. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Dynamics of Yield and Chlorophyll Content of Four Kangkung (Ipomea reptans Poir) Sequences With Soilless Cultivation System Due to Direct and Residual Effects of Vermicompost Application

The applications of organic fertilizers releasing nutrients slowly not only have a direct impact on the growing crop, but also, residual effects on the subsequent crops in the conventional crop cultivation systems. Studies on the residual effects of organic fertilizer in soilless crop cultivation are quite rare. The present study, which is a pot experiment conducted in a greenhouse, describes the dynamics of yield and chlorophyll content of kangkong as direct and residual effects of vermicompost for four consecutive plantings in soilless crop cultivation, further, compared with inorganic fertilizer treatment. The experimental design used was a randomized complete block design with different levels of vermicompost rates and a control treatment using inorganic fertilizer. The vermicompost was applied only in the first crop, while, inorganic fertilizer was supplemented in each crop. Fresh weight per plant per pot increases ~35 - 54% at the second planting compared with the first planting, thereafter, gradually decreases in subsequent planting. The content of chlorophyll A was found to be relatively constant, while the chlorophyll B content was highest in the first planting and, thereafter, subsequently decreased in further planting. The higher yields were found at 400 - 500 g pot-1 vermicompost fertilizer dose, insignificantly different from the inorganic fertilizers treatment.

Technological Quality of Sugarcane Inoculated with Plant-Growth-Promoting Bacteria and Residual Effect of Phosphorus Rates.

Phosphate fertilization in highly weathered soils has been a major challenge for sugarcane production. The objective of this work was to evaluate the foliar levels of phosphorus (P) and nitrogen (N) and the technological quality and productivity of second ratoon cane as a function of inoculation with plant-growth-promoting bacteria (PGPBs) together with the residual effect of phosphate fertilization. The experiment was carried out at the research and extension farm of Ilha Solteira, state of São Paulo, Brazil. The experiment was designed in a randomized block with three replications in a 5 × 8 factorial scheme. The treatments consisted of five residual doses of phosphorus (0, 45, 90, 135 and 180 kg ha-1 of P2O5, 46% P) applied at planting from the source of triple superphosphate and eight inoculations from three species of PGPB (Azospirillum brasilense, Bacillus subtilis and Pseudomonas fluorescens), applied in single or co-inoculation at the base of stems of sugarcane variety RB92579. Inoculation with PGPBs influenced leaf N concentration, while inoculations with Pseudomonas fluorescens and combinations of bacteria together with the highest doses exerted a positive effect on leaf P concentration. Co-inoculation with A. brasilense + Pseudomonas fluorescens associated with a residual dose of 135 kg ha-1 of P2O5 increased stem productivity by 42%. Thus, it was concluded that inoculations with Pseudomonas fluorescens and their combinations are beneficial for the sugarcane crop, reducing phosphate fertilization and increasing productivity.

Residual Effect of Sago Dregs Fertilizer to Okra (Abelmoschus esculentus) Growth and Yield in Planting Period II in Marginal Land

Aims: The research aimed to study the potential of sago dregs fertilizer residue in increasing the growth and yield of okra (Abelmoschus esculentus) in planting period II on marginal land.
 Study Design: The research was conducted using a randomized block design with a single factor.
 Place and Duration of Study: The research was conducted in Field Laboratory of Faculty of Agriculture, University of Halu Oleo, Kendari, Southeast Sulawesi, Indonesia. The study was conducted for four months.
 Methodology: Single factor design in Randomized block design was used in the research. consists of 6 treatment levels of sago dregs fertilizer residue that have been applied in the previous planting period (planting period I), namely: without sago dregs (S0), using sago dregs 5 t ha-1 (S1), 10 t ha-1 (S2), 15 t ha-1 (S3), 20 t ha-1 (S4) and 25 t ha-1 (S5). Each treatment was placed in three groups so that there were 18 experimental units. The data was analyzed using analysis of variance and continued by Tukey Test 95% confidence level.
 Results: The results generally showed that the sago dregs fertilizer residual had a significant effect on the growth and yield of Abelmoschus esculentus. The effectiveness of the residual effect of sago pulp organic fertilizer is 3.39% to 25.68% on the variable plant height, 12.77% to 24.07% on the variable stem diameter, 17.72% to 32.26% on the variable number of leaves, 23.84% to 53.03% on the variable area leaves, 24.06% to 39.15% in plant dry weight variable, 20.21% to 41.61% on the variable number of fruit and 14.46% to 34.21% on the variable weight of fruit. Strongly influenced by the dose of sago pulp organic fertilizer applied in growing season I.
 Conclusion: Residual of sago dregs fertilizer potentially increasing of okra (Abelmoschus esculentus) growth and yield in planting period II in marginal land. The effectiveness highest was achieved in the treatment of 15 t ha-1 sago dregs organic fertilizer, for all of variables observed.

English

An experiment was conducted to evaluate the residual effect of inorganic fertilizer and bioslurry application on biological yield and nutrient content of Swiss chard. The study was conducted at Döhne Agricultural Development Institute (DADI) (32°31’ 34.077” S; 27°27’ 37.473” E) in Stutterheim, Eastern Cape, South Africa. Following planting and harvesting of two Swiss chard cultivars (Fordhook giant and Star 1801) in soil incorporated with 10 L Bioslurry (50% Bio), 20 L Bioslurry (100% Bio) and 40 L Bioslurry (200% Bio), NPK 2:3:4 (30) and 0 application (control), Swiss chard was planted in the same plots without any fertilizer applications. One seedling was planted per hill and the intra and inter row spacing was 0.25 and 0.5 m, respectively. The postharvest soil analysis showed that plots that were previously treated with 40 L (200%) Bioslurry had relatively higher soil nutrient elements compared to other treatments. The interactive effect of residual fertilizer and cultivar showed that the plots previously treated with NPK 2:3:2 (30) resulted into significantly higher dry leaf mass in Star 1801 but this effect did not differ significantly with 20 L (100%) and 40 L (200%) Bioslurry in Fordhook giant. The effect on soil pH revealed that the application of fertilizers resulted in reduced pH levels in summer compared to winter irrespective of the treatment. The plant mineral analysis showed that the fertilizer residues did not significantly influence plant mineral uptake and no clear trends were observed for the tested elements. Key words: Residual effect, bioslurry, biological yield, Fordhook giant, Star 1801.

Successive lettuce cultivation on organic substrates

The purpose of the present work was to evaluate i the influence of organic compost and soil proportions on lettuce growth in greenhouse and ii - the residual effect of organic fertilization in successive lettuce crops. Six compost:soil proportions were evaluated (100:0, 80:20, 60:40, 40:60, 20:80 and 0:100) in three successive lettuce (cultivar “Monica”) crops under randomized blocks design. Stem and crown diameter, plant height, number of leaves, volume of roots, fresh weight of leaves and the aerial portion, dry weight of leaves, stem, aerial portion, roots and the total dry weight; chlorophyll A, B and total chlorophyll were evaluated. There was a significant interaction between the organic compost dosages and the successive cultivation. The effect of the cultivation periods according to the proportions showed, in a general manner, a tendency to produce higher values of CLB, ALP and DMC in the first cultivation period for the majority of proportions. The best proportion of organic compost:soil was of 60:40, in the first crop. For all successive crops, although a residual effect of the compost was detected, the proportion of 60:40 was not enough to sustain the productivity level of the first crop and therefore requiring supplementing fertilization.

Biochar Phosphate Fertilizer Loaded with Urea Preserves Available Nitrogen Longer than Conventional Urea

Biochar, a carbon-rich material obtained by pyrolysis of organic wastes, is an attractive matrix for loading nutrients and producing enhanced efficiency fertilizers. In this study, poultry litter (PL) was enriched with phosphoric acid (H3PO4) and MgO to produce a biochar-based fertilizer (PLB), which was loaded with urea in a 4:5 ratio (PLB:urea, w/w) to generate a 15–15% N–P slow-release fertilizer (PLB–N) to be used in a single application to soil. A greenhouse experiment was carried out in which a common bean was cultivated followed by maize to evaluate the agronomic efficiency and the residual effect of fertilization with PLB–N in Ultisol. Six treatments were tested, including four doses of N (100, 150, 200, and 250 mg kg−1) via PLB–N in a single application, a control with triple superphosphate (TSP—applied once) and urea (split three times), and a control without N-P fertilization. The greatest effect of PLB–N was the residual effect of fertilization, in which maize showed a linear response to the N doses applied via PLB–N but showed no response to conventional TSP + urea fertilization. Biochar has the potential as a loading matrix to preserve N availability and increase residual effects and N-use efficiency by plants.

Effects of Irrigation, Organic and Inorganic Nutrient Sources on the Growth, Yield and Soil Fertility Status With Rice-Rice Cropping

Continuous cultivation of highly exhaustive cropping sequence in most of the irrigated fertile lands has resulted in the decline of soil physico-chemical condition in general and particularly soil organic matter (SOM) content. The experiment was laid out inasplit- plot design with irrigation (I1: traditional irrigation i.e. continuous flooding, I2: saturated condition, I3: Alternate wetting and drying) in main plots and fertilizers treatments: T0 = Control, T1 =100% (Recommended dose of chemical fertilizer), T2 =50% RDCF + 5 ton cowdung ha- 1, T3=70% RDCF + 3 ton cowdung ha-1, T4 =50% RDCF + 5 ton compost ha-1, T5 =70% RDCF + 3 ton compost ha-1, T6 = 50% RDCF + 3.5 ton poultry manure ha-1, T7 =70% RDCF + 2.1 ton poultry manure ha-1to the sub - plots. The rice yields were not significantly affected by different irrigation but higher grain yields were obtained in continuous flooded irrigation. The treatment T7 gave higher Boro and T. Aman rice yields. The higher Boro rice grain yields were obtained from I1T7 (70% RDCF + 2.1 ton poultry manure ha-1 with continuous flooded irrigation) followed by I3T7 (alternate wetting and drying + 70% RDCF + 2.1 ton poultry manure ha-1). The 100% RDCF was applied to T. Aman rice resulted residual effects of fertilizer and the higher T. Aman rice yields were recorded in I2T2 (saturated condition + 50% RDCF + 3 ton cowdungha-1) followed by I2T3 (saturated condition + 50% RDCF + 3 ton cowdungha-1) treatment combinations due to more residual effects of inorganic plus manure application during Boro rice cropping. The highest organic matter level was found in post-harvest soils where inorganic fertilizer plus cowdung were used and soil pH increased by using poultry manure. The higher levels of available P and K concentrations were observed in the post experiment soils where fertilizer and manure were applied. Bangladesh Agron. J. 2021, 24(1): 71-81

Zinc and copper interactions under variable soil phosphorus and moisture conditions in selected Saskatchewan soils

This study evaluates the influence of phosphorus (P) fertilization (without and with added P fertilizer) and soil moisture (stress and no-stress) on efficacy, fate, and transformation of soil applied micronutrients such as copper (Cu), zinc (Zn), and Cu + Zn in a wheat and pea cropping sequence. Wheat was grown as first crop under controlled environment conditions in which micronutrient fertilizer treatments were applied, whereas pea was grown as following crop with recommended macronutrient fertilizers to understand the residual effects of micronutrient fertilization. The high-P fertilizer application and no-stress moisture condition produced the highest grain and straw yield of wheat. Without P fertilization, there were significant negative effects of a combined application of Cu and Zn on wheat yield in a Dark Gray Chernozem. Yield of the following pea crop did not show response to residual Cu and Zn. Micronutrient fertilization increased the Cu and Zn concentration in wheat and pea grain and straw and resulted in increased after-harvest availability and supply in soils. Apart from the increased concentration in labile fraction, a considerable amount of added Cu and Zn was occluded with organic matter and oxyhydroxide species, respectively. Molecular speciation analyses revealed that carbonate associated was the dominant form of Cu and Zn in the soils. Additional Cu species such as Cu-acetate and methoxide, and Zn species including Zn-sorbed montmorillonite species were identified. Insoluble Cu-phosphate and Zn-phosphate complexes were not identified by speciation analyses and do not appear to be a significant factor controlling Cu and Zn availability in these soils.

Residual Effect of Cow Dung Fertilizer to Corn (Zea mays L.) Growth and Yield in Planting Period II in Marginal Land

Aims: The research aimed to study the potential of cow dung fertilizer residue in increasing the growth and yield of corn plant in planting period II on marginal dry land.
 Study Design: Singel factor design in Randomized block design.
 Place and Duration of Study: The research was conducted in Field Laboratory of the Faculty of Animal Husbandry, University of Halu Oleo, Kendari, Southeast Sulawesi, Indonesia. The study was conducted for four months.
 Methodology: Single factor design in Randomized block design was used in the research. consists of 6 treatment levels of cow manure residue that have been applied in the previous planting period (planting period I), namely: without cow manure (R0), using cow manure 2.5 t ha-1 (R1), 5 t ha-1 (R2), 7.5 t ha-1 (R3), 10 t ha-1 (R4) and 12.5 t ha-1 (R5). Each treatment was placed in three groups so that there were 18 experimental units. The data was analyzed using analysis of variance and continued by Duncan’s Multiple Range Test (DMRT) 95% confidence level.
 Results: The results showed that the vegetative growth of corn plant 30 day after planting (dap) and plant yield was affected by residual effect of cow dung that applicated in the planting periode I, thus with P uptake by plant and available P in planting medium. 
 Conclusion: Plant productivity during planting period II more increased with the higher dose of cow manure applied during planting period I. The highest plant productivity (3.88 t ha-1) in planting period II was obtained by application of cow dung 12.5 t ha-1 during planting period I. While in the planting medium without cow dung, no seeds formation was found in plants.

Remineralization of a Dystric Ferralsol Using Basalt and Tephra Dusts, Effective Microorganisms Manure and NPK 20-10-10 for Radish (Raphanus sativus) Production in Bamougoum (Cameroon Western Highlands)

This paper studies the effect of basalt and tephra dusts, as alternatives to chemical fertilizers, on soil fertility and Radish (Raphanus sativus) production. The experiment was conducted in the field and in the laboratory in the years 2017 and 2018 on two separate plots so as to annul residual effects of fertilizers). The experimental design in the field was a randomized complete block design (56 m2 ), including five treatments and three replications: control (T0), basalt dust (T1), tephra dust (T2), effective micro-organism (EM) fertilizer (T3) and NPK 20-10-10 (T4). The main results show the following decreasing trend based on yield: T1>T3>T0>T4>T2. The best yields appear in T1 and T3 probably because they supplied the highest levels of soil nutrients to match the needs of the crops. Although T2 plants performed poorly, soil properties like pH.H2O (6.14 to 6.49), sum of exchangeable bases, base saturation, available phosphorus and cation balance were improved after tephra treatment. T2 plants might have performed poorly due to intrinsic properties of the tephra dust like low availability of trace elements compared to T1 and T3. T4 plants show the highest number of leaves, leaf area index and plant height. The Fe, Mn, Cu and Zn levels in bulbs and leaves will not pose danger of toxicity to human upon consumption and could serve as nutrient supplement for children and expectant mothers. The most profitable treatment is T1 permitting to recommend the popularization of basalt dust for radish cultivation as an alternative to chemical fertilizers.

Effect of boron fertilization on soil chemical properties, nutrients status in the soil and yield of crops under cauliflower-cowpea okra sequence in North East India

ABSTRACT This field investigation was conducted to assess the implication of the direct and residual effect of the applied differential level of boron on the dynamics of the soil chemical properties, nutrient status in soil and yield of crops under cauliflower–cowpea-okra cropping sequence in an Inceptisol of North East India. The imposed treatments comprise five levels of boron viz., 0, 0.5, 1.0, 1.5 & 2.0 kg ha−1 with four replications. To assess the direct effect of boron fertilization in soil, cauliflower crop was grown as a test crop. While for further assessment of concomitant residual effects of boron fertilization, cowpea and okra were grown as a test crop wherein boron fertilization was phased out in both the crops. The recommended dose of NPK fertilizer along with FYM was uniformly applied to all the crops in the cropping sequence. The experimental findings showed that amongst the applied differential levels of boron, application of 2 kg B ha−1 was realized as the most prominent boron dose responsible for increasing the maximum content of soil chemical properties, nutrient status in soil and yield of crops while the control plots recorded the lowest for all the three crops in the sequence. Principal component analysis executed in respect of soil chemical properties and soil nutrient status in cauliflower-cowpea-okra sequence explained the data variation to the tune of 77.03%, 76.52% and 70.74% of the total variability. Similarly, multiple linear regressions performed to figure out the best fitting model showed that response variable potassium attributed the highest up to 52.05% in augmenting yield of cauliflower while nitrogen accounted for 72.04% in cowpea and zinc contributed 89.55% in okra, respectively. Overall, the present findings indicated thatapplication of 2 kg B ha-1 was found to be the best treatment in improving the soil chemical properties, nutrient status in soil and yield of crops under cauliflower–cowpea- okra cropping sequence.

Long-term Fertilization with Liquid Cattle Manure Leaves Legacy Nutrients, but not Organic Carbon and Has No Effect on Soil Microbial and Physical Properties a Year after Last Application

ABSTRACT Long-term liquid cattle manure (LCM) application can enhance soil fertility, increase soil organic carbon, and improve soil properties. We investigated the residual effects of long-term fertilization with LCM on physical, chemical and microbial properties of a calcareous soil. The effects of LCM, common inorganic fertilization, recommended fertilization or non-fertilized control were investigated in field plots with corn (Zea mays L.), 1 year after the cessation of 16-years of experimentation. The residual concentrations of soil available P, K, Cu, Zn, B and total N but not NO3-N remained significantly higher with LCM, while there were no differences in soil pH, electrical conductivity and sodium adsorption ratio, compared to the other treatments. The previously observed increase of soil organic C with LCM was no longer evidenced. For aggregate size distribution and stability, microbial biomass N, easily extractable glomalin-related soil protein, number and morphotypes of arbuscular mycorrhizal fungal spores and percentage of root length colonization, there was no difference among treatments. Microbial growth and activity were limited by C, while the calcareous nature of the soil was more important than glomalin for soil aggregation. In conclusion, the residual effects of LCM were limited to soil nutrient increase.

Principal component analysis of steers performance and structural and nutritional characteristics of Mombasa grass

ABSTRACT: There is little information about whether the increased secondary productivity observed in pastures fertilized with high nitrogen rates is attributable to fluctuations in the nutritional value or pasture structural characteristics, or both. This study aimed to identify a set of factors (structural and nutritional characteristics) that best explain the performance of beef steers grazing Mombasa grass pastures under residual effects of nitrogen fertilizer. The data were collected in Mombasa grass pastures fertilized with increasing rates of nitrogen (N) (100, 200 and 300 kg ha-1) from 2015 to 2017. In 2018, nitrogen fertilization was not used in order to characterize a residual effect of the nutrient. Variables related to pasture structural characteristics such as forage accumulation rate (FAR), canopy height, forage mass (FM) and morphological components were evaluated. The study also evaluated the nutritional value of leaf blades and the performance of beef steers based on average daily gain (ADG) and stocking rate. Principal component analysis was performed using the dataset available. Most of the variance (99.6%) was explained by only two principal components (PCs), of which 90.0% corresponded to PC1. The most influential parameters for PC1, in order of priority, were: FAR, FM, leaf blade and stem masses. These variables were positively associated with stocking rate. Conversely, ADG was not associated with any variable. ADG was the most relevant variable for the second PC; however, this PC explained less variance (9.6%). The structural characteristics of the pasture (FAR, FM and morphological components mass) better explain the fluctuations in the performance of cattle on pastures of Mombasa grass under residual effects of nitrogen fertilizer. The stocking rate is an efficient parameter to support decision-making in managed pastures with variable stocking.

Direct and residual fertilizer values of maize (Zea maysL.) stover co-compostedwith Tithonia diversifolia(Hemsl.) A. Graygreen manure

The present investigation highlights and compares the direct and residual fertilizer values of maize (Zea mays L.) stover composted with Calliandra calothyrsus Meisn and Tithonia diversifolia (Hemsl.) A. Gray-green manure on maize (Zea mays L.) and successive potato (Solanum tuberosum L.). Two field studies were installed with maize and successive potato crops in a completely randomized block design (CRBD) with three replicates. Statistical analyses were performed using R commander, version 4.0.2. Grain yields, root biomass, above ground biomass and calculated parameters (Root/Shoot ratio, Harvest Index and GinningRate) were evaluated for maize. Total potato yields were evaluated and categorized into small size tubers (SST 65 mm). Treatments under evaluation were: T1=Control, T2=Farm (cow) manure alone, T3=Maize stover co-composted with Calliandra calothyrsus Meisn green manure; T4= Maize stover co-composted with Tithonia diversifolia (Hemsl.) A. Gray green manure; T5= Farm (cow) manure+45-60-30; T6= Maize stover co-composted with Calliandra calothyrsus Meisn green manure+45-60-30; T7=Maize stover co-composted with Tithonia diversifolia (Hemsl.) A. Gray green manure+45-60-30; and T8=Farm (cow) manure+FOMI Imbura+FOMI Totahaza. Obtained results indicated highest maize yields with FOMI organo-mineral fertilizers (2.7 T/ha) seconded by the recommended fertilizer practice T5 (2 T/ha). In the same line, highest R/S value (=0.38) was registered with the same FOMI treatment (T8), while the highest HI value (0.21) was observed with the maize stover co-composted with Tithonia diversifolia (Hemsl.) A. Gray (T4). Highest potato total yields were observed with the maize stover compost enriched with Tithonia diversifolia (Hemsl.) A. Gray and supplemented with mineral fertilizer (7.61 T/ha), followed by the same compost without mineral fertilizer addition (6.35 T/ha). We conclude our study with the following statements: i) the highest direct fertilizer value was observed with the FOMI treatment; ii) the residual fertilizer effects were more expressed with the maize stover co-composted with Tithonia diversifolia A. Gray green manure with or without mineral additive, followed by farm manure and maize stover enriched with Calliandra calothyrsus Meisn green manure. Consequently, we restate that the effects of compost-based organo-mineral fertilizers on crop yields should be definitely evaluated on a multiseasonal basis so as to fully capture their residual fertilizer potentials.