Fertilizer Recommendations Research Articles

Assessment of Endogenous Soil Fertility to Update Fertilization of Maize (Zea mays L) Crops in the Savannah Region of Togo

The diagnosis of soil fertility is a prerequisite for the formulation of balanced and site-specific fertilizer recommendations. Macro elements (nitrogen – N, phosphorous – P and potassium – K) based nutrient omission trials were conducted in the districts of Oti, Tandjoare, Tone and Kpendjal of the Savannah region. The objective was to assess endogenous soil fertility under maize cropping to further develop updated site-specifique fertilization schemes for the crop. A total of twenty-five producers were selected in the region (eight in Tandjoare, seven in Tone, five in Oti and five in Kpendjal) for the study in a paticipatory approach. The approach was participatory in order to involve the end user in the exercise. A randomized complete block design was adopted with five fertilization treatments including N0P0K0 (T1), N0P60K70 (T2), N120P0K70 (T3), N120P60K0 (T4) and N120P60K70 (T5) kg ha-1 for the trial. The unit plot size was 100 m2 (10 m x10 m). Grain yield, yield response to nutrients and Agronomic Efficiency (AE) were determined. Genstat Edition 12th was used to discriminate means.The average yields were 0.56, 0.83, 3.18, 3.44 and 4.57 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Tandjoare, 0.32, 0.52, 1.06, 2.39 and 3.02 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Tône, 1.01, 1.35, 2.56, 3.16 and 4.39 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Oti and 0.39, 0.75, 1.54, 2.33 and 3.31 Mg ha-1 respectively for T1, T2, T3, T4 and T5 in Kpendjal. The ranking of yield data by fertilizer treatment indicates that all three macronutrients (N, P and K) are required for maize production in the Savannah region, with a priority ranking of N>P>K. The results also showed that the best Agronomic Efficiency is obtained when all macronutrients are supplied in all four districts. The results of this diagnostic will be used as a basis for formulating balanced, site-specific fertilizer recommendations for intelligent, environmentally-friendly agriculture.

Evaluation of Balanced Fertilizer Types and Validation of Soil Fertility Map-Based Fertilizer Recommendation for Bread Wheat Production in Bale Highland Southeastern Ethiopia

The optimal and appropriate fertilizer recommendation packages for all crops considering the improvement in productivity of small-scale farmers in the country. To evaluate the impact of blended fertilizer on wheat output, a field experiment using a five-treatment, three-replicate RCBD design was carried out during the 2020–2023 cropping season at Bale Highland southeastern Ethiopia to evaluate balanced fertilizer types and validation of soil fertility map-based fertilizer recommendation for Bread Wheat production The treatment 1Control (without fertilizer)2 (100 kg/ha-1 Urea )3 (100 kg /ha-1 NPS plus 100 kg of urea)4(100 kg /ha-1 NPSB plus 100 kg of urea) 5(100 kg /ha-1 NPSZnB plus 100 kg of urea). The plot size was 3m by 3 m (9 m2) and the spacing between plots and blocks was 1m and 1m, respectively in comparison to the control, The application of 100 kg ha-1 NPSZnB + 100 kg ha-1 urea in Bale Highland produced the highest and most significant yields of grains (5257.51 kg ha-1) the least amount of grain (3006.51 kg ha-1) in Bale Highland at the same time. To improve the production of wheat in the study area, farmers in Bale Highland must apply NPSZnB, with a similar agroecology.

NITIRSOIL: A model that balances complexity with prediction uncertainty for improving nitrogen fertilization in agriculture

Mismanagement of the nitrogen (N) fertilization in agriculture leads to low N use efficiency (NUE) and therefore pollution of waters and atmosphere due to NO3− leaching, and N2O and NH3 emissions. The use of N simulation models of the soil-plant system can help improve the N fertilizer management increasing NUE and decreasing N pollution issues. However, many N simulation models lack balance between complexity and uncertainty with the result that they are not applied in actual practice. The NITIRSOIL is a one-dimensional transient-state model with a monthly time step that aims at addressing this lack in the estimation of, mainly, dry matter yield (DMY), crop N uptake (Nupt), soil mineral N (Nmin), and NO3− leaching in agricultural fields. According to its global sensitivity analysis for horticulture, the NITIRSOIL simulations of the aforementioned outputs mostly depend on the critical N dilution curve, harvest index, dry matter fraction, potential fresh yield and nitrification coefficients. According to its validation for 35 nitrogen fertilization trials with 11 vegetables under semi-arid Mediterranean climate in Eastern Spain, the NITIRSOIL presents indices of agreement between 0.87 and 0.97 for the prediction of total dry matter, DMY, Nupt, NO3− leaching and soil Nmin at crop season end. Therefore, the NITIRSOIL model can be used in actual practice to improve the sustainability of the N management in, particularly horticulture, due to the balance it features between complexity and prediction uncertainty. For this aim, the NITRISOIL can be used either on its own, or in combination with “Nmin” on-site N fertilization recommendation methods, or even could be implemented as the calculation core of decision support systems.

Update of Mineral Fertilization Recommendations for Maize (Zea mays L.) in the Savannah Region of Togo

The recommendations specific site of the nutrients in maize cultivation are necessary in the region of Savannah in Togo in the current context of the variability of the endogenous fertility of soils. To this end, based on the results of subtractive trials whose treatments were: the absolute control - N0P0K0 (T1), N0P60K70 (T2), N120P0K70 (T3), N120P60K0 (T4) and N120P60K70 (T5) kg ha-1 coupled with the maize variety Ikenne, conducted in the prefectures of the Savannah region, target yields were determined taking into account the potential yield of the Ikenne variety. Fertilization formulas to obtain the difference between the target yields and those measured on the zero N, zero P and zero K treatments were calculated. The results revealed that the gradient of priority nutrient requirement for maize was N > P > K in the prefectures. In Tandjouaré, grain yields of 3, 3.5, 4, and 4.5 Mg ha-1 were obtained with the fertilizer formulas N92P0K0, N112P10K0, N132P18K16 and N152P26K29 kg ha-1, respectively, with corresponding value/cost ratios of 16, 13, 11, and 10. In Tône, achieving grain yields of 2.5, 3, 3.5, 4, and 4.5 Mg ha-1 is subject to the fertilizer formulas N79P24K0, N99P32K16, N119P41K30, N139P49K43 and N159P57K56 kg ha-1, respectively, with corresponding value/cost ratios of 9, 8, 12, 7, and 6. In Oti, achieving grain yields of 3, 3.5, 4, and 4.5 Mg ha-1 is subject to the fertilizer formulas N66P7K0, N86P16K9, N106P24K22 and N126P32K36 kg ha-1, respectively, with corresponding value/cost ratios of 19, 14, 11, and 10. In Kpendjal, obtaining grain yields of 2.5, 3, 3.5, 4 and 4.5 Mg ha-1 is subject to fertilizer formulas N70P16K5, N90P24K18, N110P33K31, N130P41K45 et N150P49K58 kg ha-1, respectively, with corresponding value/cost ratios of 11, 9, 8, 7 and 7.

Efficacy of foliar versus soil application of micronutrients on the production of mango (Mangifera indica L.)

Soil test-based fertilizer recommendations were calculated for mango @1.25:0.60:0.90kg N: P2O5:K2O per tree and were applied for all eight treatments as per schedule in the Randomized block design in an experimental field. The pooled analysis of the results revealed that the application of Soil test based recommended dose of fertilizer application after harvest + Soil application of FeSO4 @ 200g + ZnSO4 @ 200g + MgSO4 @ 100g +CuSO4 @50g + Borax @50g + MnSO4 @ 50g+ Foliar spray (twice) of ZnSO4 (0.3%) + FeSO4 (0.5%) + CuSO4 (0.2%) + Mg SO4 (0.5%) + Borax (0.2%) + MnSO4 (0.2%) at pre-flowering and marble stage recorded the maximum individual fruit weight (592 g) and highest yield kg per tree (380) followed by the T1 + IIHR micronutrients spray (twice) with yield per tree of 336 kg/tree while the control STCR based RDF alone after harvest recorded 193 kg/tree. The leaf nutrients were analyzed after sprays of the application of T1 + Soil application of micronutrients + Foliar Spray of micronutrients (Twice) recorded the highest leaf nutrient status of Nitrogen 1.55%, Phosphorus 0.224% and Potassium 1.39% and the highest micronutrients in leaf Iron (131.80 ppm), Zinc (20.50 ppm), Copper (37.50 ppm) and Manganese (199.20 ppm) higher as above treatment while, the control recorded lower value of Iron (66.30 ppm), Zinc (9.40 ppm), Copper (31.70 ppm) and Manganese (114.20 ppm).

DRIS norms for nutritional diagnosis of dwarf cashew

Nutritional evaluation of plants through leaf tissue analysis allows diagnosing the balance between nutrients and helps in the eventual recommendation of fertilization. The objective of this study was to apply DRIS norms and establish the appropriate nutrient contents in dwarf cashew leaves. In 248 plots with the dwarf cashew clones ‘CCP 76,’ ‘Embrapa 51,’ ‘BRS 189,’ ‘BRS 226,’ ‘BRS 265’ and ‘BRS 555’ leaves were collected for analysis of macro and micronutrients, in addition to sodium, and the respective nut yields (kg ha−1) were obtained. Of the total number of plots, 128 were considered to be high-yielding, which corresponded to 51.6% of the population. The decreasing order of nutrients (plus Na) with the highest frequency of limitation due to lack in the high-yielding subpopulation was: Na > Cu > S > P > K = Mg > B > N > Mn > Fe = Zn > Ca. Nutrients (plus Na) with the highest frequency of limitation due to excess, in descending order, were: Na > S > Cu > Mn > Ca = Mg > P = Fe > K > N > B = Zn. The appropriate ranges obtained by DRIS were: 13.0-15.5, 0.8-1.1, 7.6-9.3, 1.4-2.1, 1.3-1.7, 0.7-0.9 and 1.1-1.6 g kg−1 for N, P, K, Ca, Mg, S and Na, and 9.7-19.3, 5.4-7.4, 19.3-29.8, 39.6-70.8 and 11.7-17.3 mg kg−1 for B, Cu, Fe, Mn, and Zn, respectively.

Recommendations of N, P, and K site-spesific for maize cropping in the Jeneponto District of South Sulawesi

Abstract The incompatibility of N, P, and K rates for maize plants causes a decrease in plant productivity and farmer income. Therefore, there is a need for appropriate N, P, and K fertilizer recommendations based on agroecosystems that farmers can apply. This research aims to obtain location-specific N, P, and K fertilization recommendations for maize based on the agroecosystem in Jeneponto Regency, South Sulawesi. This research was conducted in Jeneponto District, South Sulawesi, from March to October 2021. The research used a survey method adapted to the questions in the Nutrient Expert (NE) program form. The research showed that the optimum fertilizer recommendation for maize in Jeneponto District was 170 – 190 kg N ha−1, 30 – 60 kg P2O5 ha−1, and 33 – 63 kg K2O ha−1, with a 9 – 10 t/ha yield. Using these recommendations, they will gain a higher profit and R-C ratio than the farmer’s existing fertilization, namely, a profit of RP. 30,499,400 (Rp. 30,276,000 – 30,697,000) with an R-C ratio of 4.05 (3.96 – 4.13), whereas if using existing fertilization at the farmer level, they will gain a profit of Rp. 19,397,000 (Rp. 14,215,000 – Rp. 25,735,000) with an R-C ratio of 2.20 (1.81 – 2.75).

Sunflower-nitrogen calibration based on the amount of mineral nitrogen in soil under rainfed conditions in thrace region

Sunflower is grown under both rainfed and irrigated conditions in all regions to meet the vegetable oil needs of Türkiye, however, in the Thrace region, it is the main rotation crop grown under rainfed conditions after wheat. This study was conducted in the Thrace Region between 2013 and 2016 in order to evaluate the parameters that can be used as an index for nitrogen fertilization recommendations for sunflower plant. For this purpose, organic matter and saturation were determined in soil samples taken from 0-20 cm depth before the experiment and ammonium and nitrate contents were determined in soil samples taken from 0-30 cm, 30-60 cm, and 60-90 cm depths. Within the scope of the study, 27 field trials were conducted over four years. Nitrogen levels of 0 (control), 3, 6, 9, and 12 kg da-1 were implemented in the trials conducted in a Latin square experimental design. In this study, log (279.9-y) = log279.9-0.090b1-0.117x Mitscherlich calibration equations were determined based on 0-30 cm ammonium+nitrate content in the soil.

Assessment of soil fertility in jute (Corchorus olitorius L.) cultivated land and nutritive value of its plant parts

The samples of soil, leaves, and shoots of jute were collected from twenty spots of jute (variety BJRI-Tossa-8) fields from different locations in the Narail district of Bangladesh under AEZ-12 during the year 2022. The study intended to evaluate the soil’s physicochemical properties and nutrient concentrations in jute leaves and shoots of 120 days old plants (at the harvesting time of the plant). The soil pH was neutral to slightly alkaline (6.6 to 7.4), with organic matter content from 1.03 to 1.71%. Electrical conductivity was found non-saline which was 40 to 150 μS/cm at 0 to 15 cm depth. The dominant soil textural class was clay. The total N, P, and S in soils were found to be 0.21 to 0.31%, 0.027 to 0.0283% and 0.0002 to 0.0023%, respectively and available N, P, and S were found to be 0.0058 to 0.0087%, 0.0007 to 0.0018%, and 0.0001 to 0.0006%. The nutritional values of N, P, and S in leaves ranged from 3.00 to 11.75%, 0.2281 to 0.5627%, and 0.0056 to 0.0197%, respectively. The total N, P, and S concentrations in the shoots were 0.17 to 5.07%, 0.0012 to 0.2935%, and 0.0002 to 0.0011%, respectively. The study indicated that jute leaves are enriched in nutrition and may be a good source of nourishment for human health. This research also illustrated that the jute field had low to medium fertility soil status. It is suggested that the farmers of AEZ-12 should follow the fertilizer recommendation doses in jute cultivation for higher fiber yield and allow sufficient decomposition of jute roots and debris to sustain succeeding crop production and soil fertility. The study has given new information and guidelines for the researcher for future investigation. Biodivers. Conserv. Bioresour. Manag. 2024, 10(1): 35-44

Impact of varied tillage practices and phosphorus fertilization regimes on wheat yield and grain quality parameters in a five-year corn-wheat rotation system

Choosing appropriate tillage methods and applying the right amount of chemical fertilizers are pivotal for optimizing wheat management and enhancing wheat quality. This study investigated the influence of conservation agriculture and phosphorus levels on nutrient content, yield components, and quality traits of wheat in a corn-wheat rotation. Conducted over five years in field conditions, the study employed a randomized complete block design with tillage treatments (conventional tillage, CT; minimum tillage, MT; and no tillage, NT) and phosphorus levels (no fertilizer use, P0; and 100% fertilizer recommendation, PR) as factors. Soil samples were collected during the fourth year (2021–2022). Results revealed significant impacts of tillage methods and phosphorus levels on wheat straw and grain nutrient composition, yield components, and quality traits. Conventional tillage yielded the highest values for protein content (12%), Zeleny sedimentation volume (20.33 mL), hardness index (45), water absorption (64.12%), and wet gluten content (25.83%). Additionally, phosphorus fertilizer application positively influenced protein percentage, gluten weight, and gluten index. The study highlights the potential of strategic soil management, particularly conventional tillage combined with phosphorus fertilization, to enhance wheat quality and yield. By elucidating these relationships, the findings contribute to optimizing wheat cultivation practices and advancing the development of superior wheat cultivars for baking applications.

Optimizing bioenergy sorghum productivity and nutrient removal in Illinois: Impact of nitrogen fertilization under diverse marginal conditions

Context or problemBioenergy sorghum (Sorghum bicolor L. Moench) is a promising crop for contributing to the United States bioenergy supply. However, the varying limitations of the marginal lands targeted for its cultivation present a management challenge. ObjectiveThis two-year study aimed to investigate how the limitations associated with marginal cropland impact the effects of nitrogen fertilization on the yield of bioenergy sorghum and the uptake of 11 macro- (N, P, K, Ca, Mg, and S) and micronutrients (Fe, Mn, Zn, Cu, and B). MethodsThe study contrasted prime cropland in central Illinois (Urbana) with three marginal cropland sites in southern (Ewing) and central Illinois (Fairbury and Pesotum). These marginal cropland sites are characterized by varying limitations, including low soil fertility (P and K limitations), leaching and erosion, and flooding, respectively. Four nitrogen rates (0, 56, 112, and 168 kg N ha−1) were tested under eight environments. ResultsThe average yields and ranges of sorghum biomass were 20.2 (17.0–23.2) Mg ha−1 in Urbana, 18.1 (13.1–19.8) Mg ha−1 in Ewing, 13.8 (9.0–17.3) Mg ha−1 in Fairbury, and 23.3 (14.6–33.0) Mg ha−1 in Pesotum. Optimal N rates were 56 N in Pesotum and 112 N in Urbana, Ewing, and Fairbury. Tissue macronutrient contents in Urbana were generally higher than in the marginal croplands, while micronutrient contents did not show discernible trends. Increasing N rate generally correlated with the macronutrient removal except in Ewing. ConclusionComparable sorghum biomass yields were observed between prime and marginal croplands (averaging 18.3 Mg ha−1), but optimal N rates varied between 56 N and 112 N. This suggests that yield gaps can be narrowed by applying the optimal N rates for the respective locations. However, increased removals of macronutrients, especially P and K, with increasing yields indicate the need to revise fertilizer recommendations, particularly for soils deficient in these nutrients. Implications or significanceOur study suggests that while sorghum production on marginal cropland is feasible, N management needs to be adapted to the unique limitations associated with various types of marginal cropland.

A better understanding of the effectiveness of placed phosphorus fertilisation with struvite for silage maize: A pot experiment

Struvite is emerging as a circular, slow-release phosphorus (P) fertiliser. However, its effectiveness for crops and its impact on soil P tests still remain largely unclear. We analysed the effectiveness of struvite as a row fertiliser in a pot experiment with maize in a sandy soil and a loamy soil, both exhibiting a low agronomic soil P status. Maize was seeded in both soils, amended with either granular struvite or water-soluble di-ammonium phosphate (DAP) as row fertilisers. A positive control received an excess of sodium phosphate, mixed homogeneously through both soils; a negative control did not receive additional P. We measured the agronomic maize performance at the end of the vegetative growth stage (V10) and assessed the suitability of two established agronomic soil P tests (i.e. P-CaCl2 and P-AL) to predict plant-available P in the soils amended with struvite. Furthermore, we performed an additional batch experiment to better understand the dissolution dynamics of struvite during a prolonged period of extraction of soil in 0.01 M CaCl2. Placed struvite application led to a lower performance of maize in comparison to DAP in terms of biomass production as well as P uptake (53 and 71 % lower, respectively). Yet the agronomic performance of struvite in general was higher than the performance of the negative control, confirming the potential of struvite as an emerging P fertiliser. Surprisingly, both soils fertilised with struvite showed a significantly higher soil P test than any other P treatment in our pot experiment. This was an artefact due to the dissolution of residual struvite granules during the soil extraction procedures. These results call for a reconsideration of how to interpret P-CaCl2 and P-AL as a basis for P fertiliser recommendations for soils receiving struvite as a P fertiliser.

A Portable Determination Method for the Soil Rapid Available Potassium via Enhanced NaBPh4 Turbidimetry

ABSTRACT Monitoring soil rapidly available potassium (RAK) reserves is extremely significant for developing precise fertilizer recommendations. The sodium tetraphenylborate (NaBPh4)-spectrophotometer method is applied to the detection of soil RAK content as a speedy, efficient and portable approach. However, the detection accuracy of this method is inferior to the ammonium acetate (NH4OAc)-flame photometer method. Here, the detection processes of the NaBPh4 turbidimetry were optimized to find the correlation with the NH4OAc method, further discussed the reasons for the different results by the two methods. The maximum relative error is 13% after conversion through the calibration curve. In addition, the accuracy of the calibration curve was verified by selecting non-fitting soil samples from two experimental sites. Therefore, our work proposes that the NaBPh4 turbidimetry, more convenient and rapid, can accurately detect the soil RAK content in the field. It provides an experimental guidance for the detection method of soil RAK content based on ultraviolet detection and on-site rapid detection devices.

Soil biological and physical measurements did not improve the predictability of corn response to phosphorus fertilization

AbstractIncluding soil health and physical measurements with traditional soil fertility measurements has the potential to improve corn (Zea mays L.) P fertilizer recommendations. The objectives for this study were to (1) evaluate the accuracy of current South Dakota corn P recommendations in predicting yield increases and (2) determine if the predictability of yield response to P fertilization improves by including selected soil biological, physical, and chemical measurements. This project was conducted in central and eastern South Dakota from 2019 to 2022 at 117 experimental sites that varied in management, landform, and soil type. A treatment of 48.9 kg P2O5‐P ha−1 was compared to a control with no P fertilizer. Soil samples (0–15 cm) collected before fertilization were analyzed for selected soil physical, chemical, and biological parameters. Analysis suggested that the current critical P value of 16 mg Olsen‐P kg−1 was still accurate as it was still within the 68% confidence interval for the linear (12–19 mg kg−1) and quadratic plateau (16–26 mg kg−1) models. Using the critical value of 16 mg Olsen‐P kg−1, we correctly predicted P responsiveness 70% of the time. The accuracy of predicting P responsiveness was not further improved by considering selected enzymes, permanganate oxidizable C, soil respiration, total C, or total N, but was improved by considering pH, soil organic matter, and apparent cation exchange capacity. Therefore, the use of typical soil fertility measurements without soil physical and biological measurements is currently the best option for predicting the responsiveness of corn to P fertilization in South Dakota.

Models and sufficiency interpretation for estimating critical soil test values for the Fertilizer Recommendation Support Tool

AbstractSoil test correlation determines whether a soil test can be used to predict the need for fertilization based on the critical soil test value (CSTV). Our objectives were to compare the CSTV estimated from five combinations of correlation models and yield sufficiency interpretations and to select one method for soil test correlation performed with the Fertilizer Recommendation Support Tool (FRST). Four models were fit to three datasets with strong (Mehlich‐1 K), moderate (Mehlich‐3 K), or weak (Olsen P) correlations between soil test P or K and crop relative yield. We tested the arcsine‐log calibration curve (ALCC), exponential (EXP), linear plateau (LP), and quadratic plateau (QP) models. The CSTV was defined as 95% of the maximum predicted yield for the ALCC and EXP methods, the join point for LP, and both the join point and 95% of the maximum for the QP providing five CSTV predictions. The five CSTVs ranged from 46 to 66 mg kg−1 for the Mehlich‐1 K dataset, 115 to 165 mg kg−1 for the Mehlich‐3 K dataset, and 7 to 16 mg kg−1 for the Olsen P dataset. Ten pairwise comparisons showed the estimated CSTV was numerically and sometimes statistically influenced by the model and sufficiency level interpretation. Despite differences among CSTVs, the frequency of significant yield responses above and below the predicted CSTV was generally comparable among the methods, with false‐negative errors occurring at 0%–18% of sites for a given dataset. The QP model with a CSTV at 95% of the predicted maximum was selected as the modeling approach for FRST.

Combined Effect of Potassium Fertiliser, Saline Irrigation Water and Humic Acids On Soil Acidity and Yield Components of Pepper (Capsicum annuum L)

A field experiment was conducted to adapt seedlings of sweet pepper, also called “California Wonder”, to salinity and the role of humic acid and potassium fertiliser in reducing the effect of salinity on the plant. A three-factorial field experiment was conducted according to the Complete Random Block Design, with three replications during the spring season of 2018 to study the humic acid and potassium fertiliser role in enhancing the salt tolerance of pepper plants. The first factor included four levels of saline water irrigation, namely 2, 4, 6 and 8 dS.m-1. The second factor included a foliar application of three levels of humic acids i.e., 0, 25 and 50 kg.h-1. The third factor represents the addition of three levels of potassium fertiliser (potassium sulphate of 50% K2O according to the fertiliser recommendation of 0, 75 and 150 kg. h-1. The considered plant and soil traits were branch per plant, stem diameter (mm), percentage of protein in the fruits and soil pH. The results obtained from the experiment can be summed up above the treatment of air conditioning at saline level 6 ds m-1 in branch per plant with 12.3 and the most significant results obtained from the experiment can be summed up above the treatment of air conditioning at saline level 4 ds m-1 in stem diameter 2.03 mm. The results showed a decrease in branch per plant and stem diameter (mm) by increasing the salinity of irrigation water by 8 ds m-1 and the increase in the addition of humic acid and potassium fertiliser. The results showed a decrease in soil acidity (pH) increasing the salinity of irrigation and increasing fruit protein content by increasing the salinity.

Ecophysiology of Soursop Seedlings Irrigated with Fish Farming Effluent under NPK Doses

Soursop (Annona muricata L.) is a tropical fruit grown in the semi-arid region of Brazil, where problems of quantitative and qualitative scarcity of water for irrigation are frequent. Using alternative water sources, such as fish farming effluents, can increase water availability; however, it presents risks due to its high salinity levels. We aimed to evaluate the effect of irrigation with saline fish farming effluent and NPK doses on soursop seedlings’ ecophysiology. We conducted a greenhouse experiment using a randomized complete block design with a 2 × 5 factorial scheme. The factors consisted of two irrigation water sources (local supply water with 0.5 dS m−1 and fish farming effluent with 3.5 dS m−1) and five doses of NPK (25%, 50%, 75%, 100%, and 125% of the fertilizer recommendation of 100:300:150 mg dm−3 of N:P2O5:K2O for soil). The soursop seedlings showed the best growth results for plant height, stem diameter, and shoot dry mass when irrigated with low-salinity water at 95% of the recommended NPK dose. However, under saline stress, the soursop seedlings showed optimal growth when fertilized with 69% of NPK dose. We recommend the following NPK fertilization for soursop seedlings: 95:285:143 mg dm−3 of N:P2O5:K2O for those irrigated with low-salinity water and 69:207:104 mg dm−3 for those irrigated with fish farm effluent. Irrigating with fish farm effluent can be a practical option for soursop seedlings as it can help save fertilizers and promote environmental sustainability.

Analisis Biaya Pemupukan Tanaman Menghasilkan Kelapa Sawit (Elaeis Guineensis Jacq.) Divisi I Kebun Langga Payung P.T. Tapian Nadenggan

Fertilizer is one of the main factors that determines plant productivity. One alternative fertilizer cost efficiency measure that can be taken is to increase the effectiveness of fertilizers in the field (Poeloengan et. al., 2000). The aim of fertilization in the field can be formulated in general policy as follows, the target of fertilizer application is to achieve 100% fertilizer application in the field with the correct application method and the right time of fertilization and each plant receives the amount of fertilizer according to the dose specified in the fertilizer recommendations to ensure adequate plant nutrients. and achieving high production for Producing Crops (PC) (Fathoni et. al., 2011). This research uses a descriptive analysis method regarding the costs of fertilization on high-yielding oil palm plants in Division I of Langga Payung Plantation P.T. Tapian Nadenggan. Observation indicators are data on recommendations for oil palm plant fertilization (type and dose of fertilizer in 2016-2018); Fertilization realization data for 2016-2018; Fertilization recommendations and fertilizer realization are made for a period of one year. Recommendation and realization data were analyzed using Student's t-Test at α = 5% to compare data per year. Cost of fertilizing plants producing oil palm (Elaeis guineensis Jacq.) Division I Langga Payung Plantation P.T. Tapian Nadenggan is influenced by 3 components, namely: Purchase of fertilizer, transportation and wages of sowers, which is based on research data that the components of fertilizer costs in 2018 are not significantly different from the components of fertilizer costs in 2017 and 2016. Likewise, the fertilization cost component in 2017 is not significantly different from the fertilization cost component in 2016.

Tree Leaves Based Disease Prediction and Fertilizer Recommendation Using Deep Learning Algorithm

Tree Leaves Based Disease Prediction and Fertilizer Recommendation Using Deep Learning Algorithm

Soil moisture and probe characteristics affect core integrity and soil test results

AbstractProper soil sampling is critical for accurate fertilizer recommendations. Samples collected in extremely wet or dry conditions may compromise the integrity of the sample and influence analytical results. We evaluated the effects of six soil moistures, two sampling depths (0–10 and 0–15 cm), and two soil probes on soil core uniformity and soil test results. Moisture treatments encompassed a range from dry (11.2%–18.5% moisture) to saturated conditions in Captina, Dewitt, Calhoun, and Calloway silt loam soils. Core depth and dry core weight were measured in all soils, and pH and Mehlich‐3 extractable P, K, S, and Zn were assessed for Calhoun and Calloway soils. Soil moisture, probe, or their interaction influenced core depth and weight, while chemical properties were significantly affected only by soil moisture. Sampling very dry or saturated soils compromised the collection of uniform cores mainly for the 0‐ to 15‐cm depth. Soil pH tended to increase with increasing moisture, but the mean values fluctuated only ±0.3 units. Across soils and depths, extractable S consistently decreased by 16%–48% as soil moisture at sampling time increased. Phosphorus was affected by soil moisture for 0–15 cm samples in both soils but showed no clear pattern. Soil moisture at the time of sampling affected soil test K for both soils and sample depths with individual cores varying up to 47 mg kg−1 (i.e., 59–106 mg kg−1). Greater soil test P and K variability occurred for very dry and wet conditions, which often prohibit collecting samples to the proper depth and could impact fertilizer rate recommendations.