Modelling maize grain yield and nitrate leaching from sludge-amended soils across agro-ecological zones: A case study from South Africa

When applying municipal sludge according to crop N requirements, the primary aim should be optimizing sludge application rates in order to maximize crop yield and minimize environmental impacts through nitrate leaching. Nitrate leaching and subsequent groundwater contamination is potentially one of the most important factors limiting the long-term viability of sludge application to agricultural soils. This study assessed maize grain yield and potential nitrate leaching from sludge-amended soils, using the SWB-Sci model, based on crop nitrogen requirements and inorganic fertilizer. The following hypotheses were tested using the SWB-Sci model and 20 years of measured weather data for 4 of the 6 South African agro-ecological zones. Under dryland maize cropping, grain yield and nitrate leaching from sludge-amended soils compared to inorganic fertilizer: (1) will remain the same across agro-ecological zones and sites, (2) will not vary across seasons at a specific site, and (3) will not vary across soil textures. Model simulations showed that annual maize grain yield and nitrate leaching varied significantly (P > 0.05) across the four agro-ecological zones, both for sludge-amended and inorganic fertilizer amended soils. The annual maize grain yield and nitrate leaching from sludge-amended soils were 12.6 t∙ha-1 and 32.7 kgNO3-N∙ha−1 compared to 10.2 t∙ha-1 and 43.2 kgNO3-N∙ha−1 for inorganic fertilizer in the super-humid zone. Similarly, maize grain yield and nitrate leaching varied significantly across seasons and soil textures for both sludge and inorganic fertilizer amended soils. However, nitrate losses were lower from sludge-amended soils (2.3–8.2%) compared to inorganic fertilizer (11.1–26.7%) across all zones in South Africa. Therefore, sludge applied according to crop N requirements has a lower environmental impact from nitrate leaching than commercial inorganic fertilizer. Further validation of these findings is recommended, using field studies, and monitoring potential P accumulation for soils that received sludge according to crop N requirements.

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Residual effect of leguminous crops and inorganic fertilizer on soil properties and maize grain yield

Acta Agronomica Hungarica ◽

10.1556/aagr.56.2008.3.5 ◽

2008 ◽

Vol 56 (3) ◽

pp. 295-301

Author(s):

J. Asibuo ◽

E. Safo ◽

B. Asafo-Adjei ◽

P. Osei-Bonsu

Keyword(s):

Organic Matter ◽

Grain Yield ◽

Soil Properties ◽

Sub Saharan Africa ◽

Inorganic Fertilizer ◽

Mucuna Pruriens ◽

Area Index ◽

Maize Grain Yield ◽

Leguminous Crop ◽

Maize Grain

Soil management practices that utilize organic matter have great potential to increase productivity in sub-Saharan Africa. Field studies were carried out between September 1995 and August 1998 to determine the effects of three leguminous crop species: velvet bean ( Mucuna pruriens var. utilis ), groundnut ( Arachis hypogaea L.) and cowpea ( Vigna unguiculata (L.) Walp), and inorganic fertilizer on the soil properties and succeeding maize grain yield when grown in rotation on a sandy soil classified as Haplic Lixisol in the forest-savannah transition zone of Ghana. The legumes were established in the minor seasons and maize in all the plots in the major cropping seasons. A 2 × 3 factorial design laid out in a randomized complete block was used. The main plots consisted of three leguminous crop residues and the sub-plots of two fertilizer levels (0 and 45 kg N ha −1 , 19 kg P ha −1 , 19 kg K ha −1 ). The control consisted of maize following maize with the recommended fertilizer rate (90 kg N ha −1 , 37 kg P ha −1 , 37 kg K ha −1 ). On average the Mucuna plots added 4.0 t ha −1 of crop residue to the soil in a season and cowpea 1.0 t ha −1 . The preceding crops had little effect on the soil properties. Leaf area index, total dry matter and maize grain yields were significantly affected by fertilizer. The best maize grain yield (6787 kg ha −1 ) was recorded in the first year on Mucuna plots with half the recommended rate of fertilizer. The cropping sequence with Mucuna residue was the most efficient. The gap in maize grain yield between the fertilized and unfertilized treatments widened each successive year. The interaction between organic matter and fertilizer may have been limited due to the surface application of the organic residue.

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Lime, manure and Inorganic Fertilizer Effects on Soil Chemical Properties, Maize Yield and Profitability in Acidic Soils in Central Highlands of Kenya

Asian Journal of Environment & Ecology ◽

10.9734/ajee/2021/v16i330250 ◽

2021 ◽

pp. 40-51

Author(s):

W. Winnie Kimiti ◽

M. W. Mucheru-Muna ◽

J. N. Mugwe ◽

K. F. Ngetich ◽

M. N. Kiboi ◽

...

Keyword(s):

Grain Yield ◽

Chemical Properties ◽

Maize Yield ◽

Sub Saharan Africa ◽

Inorganic Fertilizer ◽

Soil Chemical Properties ◽

Fertilizer Treatment ◽

Acidic Soils ◽

Maize Grain Yield ◽

Maize Grain

In Sub-Saharan Africa (SSA), acidic soil covers 29% of the total area. About 13% of the Kenyan total land area has acidic soils, widely distributed in croplands of the central and western Kenyan regions. The high soil acidity, coupled with soil nutrient depletion, negatively affects crop productivity in the region. We conducted an on-farm experiment to determine the effect of lime, manure, and phosphatic fertilizer application, either solely or combined, on soil chemical properties, maize yield, and profitability in acidic soils of Tharaka Nithi County, Kenya. The treatments were different rates of manure, lime, and P fertilizer. The experiment was designed as a randomized complete block design replicated ten times in farmer’s fields. Soil sampling was done at a depth of 0-20 cm prior to the start of the experiment, after crop harvest of SR2016 and LR2017 seasons. The samples were analyzed in the laboratory following standard methods. Results showed that lime significantly increased soil pH by 10.6% during the SR2016 and by 17.7% during the LR2017. Similarly, treatments with lime reduced exchangeable acidity and increased soil available P. Treatments with inorganic fertilizers had significantly higher maize grain yield in comparison with treatments with the sole application of lime, manure, and lime + manure. Lime + fertilizer + manure treatment gave the highest average maize grain yield (5.1 t ha−1), while control gave the lowest (1.5 t ha−1) during the LR2017 season. Economic returns were low due to the prevailing low rainfall experienced during the study period during the SR2016 season. Lime combined with inorganic fertilizer treatment recorded the highest returns (128.75 USD ha-1) followed by sole inorganic fertilizer (105.94 USD ha-1) during the LR2017 season. The study recommends a combination of both lime and inorganic fertilizer for enhanced maize production and profitability in Tharaka-Nithi County, Kenya.

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Effects of improved pigeonpea fallows on biological and physical soil properties and their relationship with maize yield

Agroforestry Systems ◽

10.1007/s10457-021-00598-7 ◽

2021 ◽

Vol 95 (2) ◽

pp. 443-457

Author(s):

Misheck Musokwa ◽

Paramu L. Mafongoya

Keyword(s):

South Africa ◽

Grain Yield ◽

Soil Properties ◽

Maize Yield ◽

Improved Fallows ◽

Soil Macrofauna ◽

Maize Grain Yield ◽

Continuous Maize ◽

Maize Yields ◽

Maize Grain

AbstractDeclining soil properties have triggered lower maize yields among smallholder famers in South Africa. Legume trees such as pigeonpea can be used as improved fallows to replenish degraded soils. The objectives of the study were to: (1) examine the effects of improved pigeonpea fallows on enhancing biological, physical soil properties and maize yield responses and (2), analyze the relationship of maize grain yield to biological and physical soil properties after improved pigeonpea fallows at Wartburg, South Africa. Pigeonpea fallows were established in 2015/16 season and terminated in 2017 and subsequently maize was planted. A randomized complete block design replicated three times was used with five treatments: continuous sole maize without fertilizer (T1), natural fallow then maize (T2), pigeonpea + grass—pigeonpea then maize (T3), maize + pigeonpea—pigeonpea then maize (T4), two-year pigeonpea fallow then maize (T5). Improved pigeonpea fallows increased maize yields through improvement in soil macrofauna species abundance, richness and diversity, aggregate stability, infiltration rate. Pigeonpea fallows increased maize yield by 3.2 times than continuous maize without fertilizer. The maize grain yield (3787 kg ha−1), was the highest on two-year pigeonpea fallows while continuous maize without fertilizer had the least (993 kg ha−1). There was a significant positive correlation between soil macrofauna indices and physical soil properties to maize yields. Smallholders who have limited access to fertilizers can sustainably use improved fallows to restore degraded soils to achieve higher maize yields in South Africa.

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Integrating Soybean Residues With Nitrogen Fertilizer for Improved Maize Production in Eastern Uganda

Journal of Agricultural Science ◽

10.5539/jas.v11n8p206 ◽

2019 ◽

Vol 11 (8) ◽

pp. 206

Author(s):

B. Sadina ◽

A. Amoding ◽

R. Amayo ◽

M. Biruma

Keyword(s):

Grain Yield ◽

Block Design ◽

Farming Systems ◽

Crop Productivity ◽

N Fertilizer ◽

Maize Production ◽

Ecological Zones ◽

Maize Grain Yield ◽

Maize Grain ◽

Four Levels

Soybean has become one of the dominant crops in Ugandan farming systems; however the contribution of its residues to improve soil and crop productivity is less known. To investigate the role of soybean residues to enhance crop productivity, researcher-managed experiments were conducted for two seasons (2011B and 2012A) in Namayingo and Tororo districts, representing the L. Victoria crescent, and South-eastern L. Kyoga basin agro-ecological zones, respectively. Factorial treatments of three levels of soybean residues (0, 2 and 4 t ha-1) and four levels of N fertilizer (0, 30, 60 and 120 kg ha-1 N) in form of urea were applied in maize fields in a randomized complete block design so as to; determine the optimum nutrient combination for maize, and establish the added yield benefits, if any, of using soybean residues with N fertilizer in maize production. Site yields varied significantly (p < 0.001), with higher maize yields obtained in Namayingo compared to Tororo. Significantly (p < 0.05) higher maize grain yields were obtained with the highest nutrient input combinations of 2 t ha-1 residue and 60 kg ha-1 N (yield increment of 71.72% above the control) in Namayingo district and 4 t ha-1 residue combined with120 kg ha-1 N increased maize grain yield by 140.69% above the control in Tororo. The added maize grain yield benefits ranged from 2540 kg grain ha-1 to 3250 kg grain ha-1 in Namayingo and from 2000 kg grain ha-1 to 2310 kg grain ha-1 in Tororo. Combined use of soybean residue with N fertilizer has been found to have agronomic yield benefits to maize production.

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Modelling N mineralisation from sludge-amended soils across agro-ecological zones: A case study from South Africa

Ecological Modelling ◽

10.1016/j.ecolmodel.2015.11.019 ◽

2016 ◽

Vol 322 ◽

pp. 19-30 ◽

Cited By ~ 6

Author(s):

Z.M. Ogbazghi ◽

E.H. Tesfamariam ◽

J.G. Annandale

Keyword(s):

South Africa ◽

N Mineralisation ◽

Amended Soils ◽

Ecological Zones ◽

Agro Ecological Zones

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Analysis of the moisture content of maize kernels in over-ripe plants

Acta Agronomica Hungarica ◽

10.1556/aagr.54.2006.4.5 ◽

2006 ◽

Vol 54 (4) ◽

pp. 425-430

Author(s):

T. Árendás ◽

L. C. Marton ◽

P. Bónis ◽

Z. Berzsenyi

Keyword(s):

Linear Regression ◽

Moisture Content ◽

Grain Yield ◽

Equilibrium Moisture Content ◽

Weather Conditions ◽

Positive Correlation ◽

Maize Grain Yield ◽

Maize Grain ◽

Maize Kernels

The effect of varying weather conditions on the moisture content of the maize grain yield was investigated in Martonvásár, Hungary from late August to late September, and from the 3rd third of September to the 1st third of Novemberbetween 1999 and 2002. In every year a close positive correlation (P=0.1%) could be observed between the moisture content in late September and the rate of drying down in October. Linear regression was used each year to determine the equilibrium moisture content, to which the moisture content of kernels returned if they contained less than this quantity of water in late September and harvesting was delayed. In the experimental years this value ranged from 15.24-19.01%.

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