Traditional Tillage Practices Research Articles

Tillage practices in the north west region of Cameroon and their consequences on soil physio-chemical properties - a review

Tillage practices make up one of the most essential operations executed on the soil during crop production. They manipulate the soil by mechanical means using tools, implements, and powered machinery with the intention to prepare the soil and make it suitable for plant growth. For the adoption of sustainable agriculture, tillage practices carried out in a particular region and their consequences on soil health need to be assessed. This review article identified traditional, conventional, and conservation tillage as the major tillage systems employed by farmers during crop cultivation in the North West Region of Cameroon. Traditional tillage practices (traditional ridging, burning in ridges (“Ankara”), and slash and burn) were highly predominant especially among small-holder farmers, followed by conservation tillage. Conventional tillage practices were the least practiced among farmers. Due to the less adoption of conventional and conservation tillage, soils in the region are mainly affected by the identified widely used traditional tillage practices. Traditional ridging exerted beneficial effects on the soil such as improved soil water conservation, increased soil nitrogen, and soil organic matter contents while burning in ridges and slash and burn exerted negative consequences on the soil by declining soil fertility, destroying soil physical properties and reducing overall land productivity. Due to the adoption of poor tillage techniques, soil degradation is rampant in the region placing the population at risk of low land productivity and food insecurity. The adaptation of improved tillage practices such as traditional ridging is thus required for sustainable soils and increased food security. Int. J. Agril. Res. Innov. Tech. 14(1): 70-76, June 2024

Physicochemical characterization of agricultural soils under a traditional system in the Mezquital Valley, Hidalgo

The study examines alkaline and sodic soils, characterized by a pH exceeding 7.5 and elevated exchangeable sodium, indicative of deficiencies in nitrogen, manganese, iron, zinc, and copper in crops. Its objective is to characterize agricultural soils under traditional and conventional systems using physical and chemical parameters to advocate for regenerative agriculture. Sampling and analysis adhere to Nom-021-RECNAT-2000 standards. Predominantly, the soils exhibit clay loam and sandy loam textures across Tula de Allende, Tezontepec de Aldama, Francisco I. Madero, and San Salvador municipalities. Organic matter percentages vary, classified as very high (Tula de Allende and San Salvador), high (Tezontepec de Aldama, Mixquiahuala de Juárez, and Francisco I. Madero), and low (Santiago de Anaya). The pH ranges from moderately alcaline to highly alkaline. Cation exchange capacity in irrigation zones varies from very high to high, and medium for Tezontepec and Santiago de Anaya, which rely on rainfed irrigation. Elevated nitrate (NO3-), phosphorus (H2PO4-), and potassium (K+) concentrations are noted across different municipalities. These findings prompt reconsideration of traditional tillage practices that exacerbate sodicity in agricultural soil.

Conservation tillage facilitates the accumulation of soil organic carbon fractions by affecting the microbial community in an eolian sandy soil.

Conservation tillage (CT) is an important agronomic measure that facilitates soil organic carbon (SOC) accumulation by reducing soil disturbance and plant residue mulching, thus increasing crop yields, improving soil fertility and achieving C neutrality. However, our understanding of the microbial mechanism underlying SOC fraction accumulation under different tillage practices is still lacking. Here, a 6-year in situ field experiment was carried out to explore the effects of CT and traditional tillage (CK) practices on SOC fractions in an eolian sandy soil. Compared with CK, CT increased the particulate OC (POC) content in the 0-30 cm soil layer and the mineral-associated OC (MAOC) content in the 0-20 cm soil layer. Moreover, tillage type and soil depth had significant influences on the bacterial, fungal and protistan community compositions and structures. The co-occurrence network was divided into 4 ecological modules, and module 1 exhibited significant correlations with the POC and MOC contents. After determining their topological roles, we identified the keystone taxa in the network. The results indicated that the most common bacterial taxa may result in SOC loss due to low C use efficiency, while specific fungal (Cephalotrichum) and protistan (Cercozoa) species could facilitate SOC fraction accumulation by promoting macroaggregate formation and predation. Therefore, the increase in keystone fungi and protists, as well as the reduction in bacteria, drove module 1 community function, which in turn promoted SOC sequestration under CT. These results strengthen our understanding of microbial functions in the accrual of SOC fractions, which contributes to the development of conservation agriculture on the Northeast China Plain.

Conservation Agriculture: A Long-term Approach towards Sustainability

With the application of intensive agricultural techniques, conventional agriculture has been successful in meeting production goals but has also led to the depletion of natural resources. Sustainability in the management of the natural resource base is necessary for ongoing and expanded agricultural output to provide food security for future generations. Over a long period, the traditional tillage practice has led to the destruction of the natural resource base of the land. As a result of its inherent connection to the physical, chemical, and biological aspects of soil, it has led to a significant loss of soil and SOM, which is a crucial component of soil quality. Therefore, a suitable cropping system and land use must be implemented and adopted to ensure food security on a sustainable basis. These measures should be based on principles to prevent land degradation, protect the natural resource base, and improve food and nutritional security through crop diversification and optimal rotation. The one sustainable cropping method that may reverse soil erosion, increase crop output, and improve the socioeconomic status of small landholder farmers is conservation agriculture (CA). Conservation agriculture (CA) is the integrated management of the available natural resources such as soil, water, flora, and fauna, with certain outside inputs to maximize the effectiveness of natural resource utilization. To fulfill the objective of sustainable crop production, an alternative approach known as conservation agriculture has emerged. It represents a significant advance in the direction of sustainable agriculture. This article reviews the emerging concerns due to the continuous adoption of conventional agriculture systems, contrasting features between conventional and conservation agriculture systems, and various principles and practices in conservation agriculture. It also highlights the benefits and limitations of CA and various challenges in the adoption of CA.

Effect of Mulching and Tied Ridge on Crop Production and Soil Improvement in Dry Land Areas

Rain fed crop production in dryland areas is unreliable due to high evapo-transpiration, high run-off rates, delay onset, and early cessation of rains. So soil moisture deficiency is one of the primary factors that limit crop production in the area. Soil conservation is another important issue in dryland areas because high run-off rates leads to severe soil erosion. Due to shortage of soil moisture there have been attempts to optimize crop yield by planting drought-tolerant crops, particularly maize, sorghum and millet. This is not enough because crop failure due to water stress is still observed in dry lands. Therefore the proper use of soil moisture conservation structures like tied ridge helps to reduce the runoff rate, nutrient losses from soil and improve the soil moisture for plant growth which in turn, boost the productivity of land and plants. In addition to tied ridge mulching is a good practice used to reduce soil erosion and enhance water conservation. Tied ridge is one of the structures used to reduce water runoff and increase infiltration of rain water to the soil. It is a form of micro-basin tillage which consists of ridging the soil typically to heights of 0.20 to 0.30 m and is blocked with earth ties spaced considering slope of the land. Tied-ridging increased soil water by more than 25% compared to the traditional tillage practice in northern Ethiopia. It has been reported that tied ridging is beneficial for increasing crop yield. Tied-ridging increased sorghum grain yield by more than 40% compared to the traditional tillage practice in northern Ethiopia. It has beneficial effects of reducing runoff loss and soil loss. Mulching is also on the positive side of the balance in dry land. When adequate residues are available and conservation tillage is used, soil erosion is greatly reduced and water conservation is enhanced. Management of crop residues on the farm lands increased the grain yields of maize, sorghum and wheat crops both by improving soil fertility and conserving water at Haramaya area. Mulch conserved more water and led to higher dry matter and grain yields of maize compared to minimum tillage.

Effect of long-term tillage and cropping system on portion of fungal and bacterial necromass carbon in soil organic carbon

The microbial necromass carbon (M-C) is considered to be relatively stable and important part of SOC. However, knowledge about the contribution of M-C storage in increasing SOC storage and the influences of tillage and cropping systems on fungal and bacterial necromass carbon (F-C and B-C) is lacking, especially in the long-term. Here, a subset of treatments in a long-term 16-year study was used to evaluate these changes. The treatments selected for present study were: (1) NTCS: no-tillage with two year corn-soybean (CS) rotation (Zea mays L. – Glycine max Merr.); (2) MPCS: moldboard plowing with two year corn-soybean rotation; (3) NTCC: no-tillage with continuous corn (CC); (4) MPCC: moldboard plowing with continuous corn; (5) CTCC: conventional tillage with continuous corn and no residue return (traditional tillage practice in China). Amino sugars were measured to calculate the M-C, F-C and B-C and their storage. Three-way ANOVA showed that tillage, depth and their interactions had significant effect on all amino sugars. However, two-way ANOVA in separate layers showed the effects of tillage on all amino sugars mostly occurred in 0–5 cm layer. A decaying exponential model showed the relationship between the M-C and SOC (R2 = 0.87). Tillage showed great effects on the amount of M-C, F-C and B-C storage but had no influence on the proportion of their distribution in SOC storage (%). More than half of the increase in SOC storage existed as M-C storage under CC cropping due to returned residue, which was higher than CS. F-C storage % was not affected by agriculture management (residue return, tillage and cropping), whereas B-C storage % was affected by both quantity and quality of residue. The results suggested that CC cropping system was better for M-C sequestration and that bacteria were relatively more sensitive to agriculture management than fungi.

ИЗМЕНЕНИЕ ПОЧВЕННОГО ПЛОДОРОДИЯ И УРОЖАЙНОСТИ КУКУРУЗЫ В ЗАВИСИМОСТИ ОТ СИСТЕМ ОСНОВНОЙ ОБРАБОТКИ

Tillage system is one of the factors that influences crop yield. The aim of the research was to determine the influence of the basic tillage systems on the change in soil fertility, yield and quality of corn grain in the soil and climatic conditions of the central zone of the Krasnodar Territory. The surveys were conducted in 2018–2020 on the experimental fields of the FSBSO “National Center of Grain named after P. P. Lukyanenko”. Soil – chernozems leached. All the experiments were carried out according to the standard methodology. In a stationary experiment, observations were performed to study several tillage practices: conventional tillage (25 cm depth plowing), mulch tillage with soil decompaction (reduced tillage done with a chisel plow to a depth of 32 cm for row crops), mulch tillage (deep tillage is excluded, disking to a depth of 10 cm twice or thrice is used instead). Plowing to a 25 cm depth improves the bulk of the soil in the 0–30 cm layer. However, chiseling to a depth of 32 cm and disking to a depth of 10 cm twice or thrice caused soil compaction. Standard tillage practice led to a decrease in the number of agronomically valuable aggregates (61.1 %) and their water resistance (59.4 %) compared to soil decompaction and minimum-tillage systems. The highest rates of productive moisture reserves were on the plots with traditional tillage and decompaction (140.6 and 141.5 mm, respectively, which is 14.7 % higher compared to the minimum mulching). The studied soil cultivation systems did not affect “1000-grain weight” but significantly affected the yield of grain from one ear (124.3 g) and the number of formed ears per one plant (1.04 pcs.). The corn yield on the fields with traditional and decompaction tillage methods was 56.9 and 55.9 c/ha, respectively; on minimum-tillage system, it decreased by 4.8 %. Protein content in grain harvested from the plots with traditional tillage practice was 11.4 %, which is higher compared to the minimum-tillage system. No significant differences were detected for crude ash and dry matter.

Model prediction capacity of ephemeral gully evolution in conservation tillage systems

AbstractEphemeral gully (EG) erosion has an important impact on agricultural soil losses and increases field surface hydrology connectivity and transport of pollutants to nearby water bodies. Watershed models including an EG component are scarce and not yet properly evaluated. The objective of this study is to evaluate the capacity of one such tool, AnnAGNPS, to simulate the evolution of two EG formed in a conservation tillage system. The dataset for model testing included runoff measurements and EG morphological characteristics during 3 years. Model evaluation focused on EG evolution of volume, width, and length model outputs, and included calibration and testing phases and a global sensitivity analysis (GSA). While the model did not fully reproduce width and length, the model efficiency to simulate EG volume was satisfactory for both calibration and testing phases, supporting the watershed management objectives of the model. GSA revealed that the most sensitive factors were EG depth, critical shear stress, headcut detachment exponent coefficient b, and headcut detachment leading coefficient a. For EG outputs the model was additive, showing low sensitivity to interactions between the inputs. Prediction of EG spatial evolution on conservation tillage systems requires improved development of gully erosion components, since many of the processes were developed originally for traditional tillage practices or larger channel systems. Our results identify the need for future research when EG form within conservation tillage systems, in particular to study gully headcut, soil erodibility, and width functions specific to these practices.

GROWTH AND YIELD INDICES OF CASSAVA (MANIHOT UTILISSIMA) AND SOIL PHYSICO-CHEMICAL PROPERTIES AS AFFECTED BY DIFFERENT TRADITIONAL TILLAGE PRACTICES IN A HUMID ENVIRONMENT

The study was conducted to assess the effects of traditional tillage practices namely No-till, Ridge-till and Mound-till, on cassava growth parameters and soil physico-chemical properties. It was a factorial experiment laid out in a randomised complete block design replicated 3-times. The factors were the 3-tillage methods and cassava plant as a test crop. Data collected on soil properties include the particle size distribution, soil bulk density, soil water content, hydraulic conductivity, soil pH, soil organic carbon, total nitrogen, available phosphorus and exchangeable bases, while data collected on plant growth and yield indices include; plant height, stem girth, number of leaves, number of tubers, tuber length and weight of tubers. The data were collected at 2, 4, 6, 8, 10 and 12 months but cumulated at 12 months after planting. The data were subjected to analysis of variance and relationship between cassava tuber yield and some soil properties measured. Results of the study showed that there was no significant difference between Ridge and Mound-till. The Ridge-till and Mound-till systems significantly influenced plant height, stem girth, number of leaves, tuber weight and total yield of cassava than No-till system, hence were recommended of increased yield of cassava in the study area.

GROWTH AND YIELD INDICES OF CASSAVA (MANIHOT UTILISSIMA) AND SOIL PHYSICO-CHEMICAL PROPERTIES AS AFFECTED BY DIFFERENT TRADITIONAL TILLAGE PRACTICES IN A HUMID ENVIRONMENT

The study was conducted to assess the effects of traditional tillage practices namely No-till, Ridge-till and Mound-till, on cassava growth parameters and soil physico-chemical properties. It was a factorial experiment laid out in a randomised complete block design replicated 3-times. The factors were the 3-tillage methods and cassava plant as a test crop. Data collected on soil properties include the particle size distribution, soil bulk density, soil water content, hydraulic conductivity, soil pH, soil organic carbon, total nitrogen, available phosphorus and exchangeable bases, while data collected on plant growth and yield indices include; plant height, stem girth, number of leaves, number of tubers, tuber length and weight of tubers. The data were collected at 2, 4, 6, 8, 10 and 12 months but cumulated at 12 months after planting. The data were subjected to analysis of variance and relationship between cassava tuber yield and some soil properties measured. Results of the study showed that there was no significant difference between Ridge and Mound-till. The Ridge-till and Mound-till systems significantly influenced plant height, stem girth, number of leaves, tuber weight and total yield of cassava than No-till system, hence were recommended of increased yield of cassava in the study area.

Chemical diversity and molecular signature of soil humic fractions used as proxies of soil quality under contrasted tillage management

Increasing food production while avoiding the progressive degradation of agricultural soils has become one of the major challenges at a global level. In consequence, the development of sustainable tillage methodologies or cultivation strategies is an important subject of current research. In fact, it has been observed that the implementation of reduced tillage (RT) vs. traditional tillage (TT) in the long term not only improves soil physicochemical properties but also global soil quality in terms of soil health. In particular, the increase of the soil organic carbon (SOC) content under RT conditions is one of the most important factors, but there is little information about the chemical composition and humification level of this carbon, and thus about its persistence at long-term. This is of particular importance considering the policies of carbon sequestration and climate change mitigation, such as the “4 per 1000” initiative. In this study, molecular-level characterization of the humic acid (HA) and fulvic acid (FA) fractions isolated from a soil after 19 years under RT and TT practices was carried out. This study would provide objective descriptors of the impact of these two tillage practices in the chemical composition of the resulting SOC. With this purpose, the potential of Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS) for assessing changes in the molecular assemblages released from the humic fractions (HA and FA) was examined. The results showed enhanced diversity and chemical richness (expressed as number of molecular formulas) in the composition of SOC under RT. Different tillage-specific compound classes were associated with both tillage practices. As a whole, the humic fraction showed a higher proportion of molecular formulas for lipid and hydroaromatic families in the case of RT compared to TT, while the same fraction under TT showed a greater richness of oxidized protein-derived formulas than RT. In the case of FAs, a similar pattern was observed for hydroaromatic and protein-derived formulas, but the proportion of molecular formulas assigned to unsaturated lipids was higher in TT than in RT. In addition, increased number of formulas for aromatic and condensed aromatic compounds was observed in FAs under TT respect to RT.

Effects of tillage and sowing practices on plant growth, soil nutrient uptake and utilization of wheat after rice

From 2016 to 2018, a field trial on three tillage and sowing practices, deep rotary tillage before sowing (DRT), shallow rotary tillage with simultaneous sowing (SRT), and strip tillage under no tillage conditions along with sowing (NT), was conducted to evaluate shoot growth, soil nutrient uptake, and utilization of wheat (Triticum aestivum) after rice (Oryza sativa) in Guanghan, Sichuan Province, China. Compared with DRT, both SRT and NT improved tillering capacity and fertile shoot rate. In 2016-2017, grain yield did not differ among the treatments, whereas in 2017-2018, NT had significantly higher grain yield (10.9%) than DRT. Furthermore, the diffe-rence in dry matter accumulation among the treatments mainly occurred prior to wheat jointing. Total nitrogen uptake of plants was higher by 9.9% in NT than in DRT, whereas nitrogen harvest index was higher in DRT than in NT. Total phosphorus uptake was not different among the treatments. Total potassium uptake was higher in NT plants than in DRT plants. Overall, the results showed that compared with the traditional tillage practice (i.e., DRT), strip tillage practice along with sowing (i.e., NT) is an effective method for increasing grain yield and soil nutrient uptake for wheat after rice.

Carbon sequestration and selected hydraulic characteristics under conservation agriculture and traditional tillage practices in Malawi

Conservation agriculture (CA) is increasingly promoted among smallholder farmers of sub-Saharan Africa in a quest to improve food security while sustaining the natural resource base of the agro-ecosystems where agriculture is based. The aim of this study was to investigate the effects of CA and traditional tillage on soil organic carbon (SOC) and selected hydraulic properties in two contrasting agro-ecological zones of Malawi. Six farmers hosted on-farm trials in each location, with each farmer having the following treatments: CA with continuous sole maize (CA-SM), CA with maize–legume intercrops (CA-ML), and traditional tillage with continuous sole maize (CT-SM). Soil samples were randomly collected in October 2015, from farmers’ fields located in Chipeni, Chinguluwe, Lemu, and Zidyana where CA had been implemented for 10 years (2005–2015) at six depth intervals: 0–10, 10–20, 20–40, 40–60, 60–80, and 80–100 cm. Bulk density, soil water characteristics, and pore size distribution were determined using undisturbed core samples. At all sites, CA improved total SOC, carbon stocks, and the stable fraction of particulate organic carbon. Maize–legume intercropping under CA had 35%, 33%, and 73% more total SOC than CT-SM in Chipeni, Lemu, and Zidyana respectively. In Chinguluwe and Lemu, CA-ML had 0.54 and 0.50 g kg–1 respectively more stable fraction of particulate organic carbon (POMP) than CT-SM; whereas in Chipeni, CA-SM had 0.73 g kg–1 higher POMP compared with CT-SM. CA also improved soil porosity, pore size distribution, and water retention capacity by increasing the proportion of mesopores and micropores compared with CT-SM. Thus, changing management practices from CT-SM to CA has the potential to improve the soil organic matter and soil hydraulic properties across agro-ecological zones in Malawi, which is important for sustainable agriculture. Farmers should be encouraged to minimise tillage, retain residues as mulch on the soil surface, and practice crop rotation.

Using beryllium-7 to evaluate soil erosion processes in agricultural lands in semiarid regions of Central Argentina

This work presents the results of a soil erosion study using the 7Be technique. This technique estimates the water erosion/deposition from the comparison between 7Be soil content of a reference site and an eroded or sedimented site. The soil samples were collected from an agricultural area of the semiarid region of Argentina near San Luis City, which has a marked rainfall season. The area has been used for crop cultivation, being subjected to plowing practices. The 7Be in the Reference Site was in the first centimeter of soil, showing the typical exponential decreasing of 7Be soil content with depth, with the 7Be inventories value being 340 ± 50 Bq m−2 for the dry season and 571 ± 48 Bq m−2 for the rainy season. The 7Be technique was applied to a potential eroded site subjected to traditional tillage practices (plowing). A net soil erosion value of 13.5 t ha−1 (1.35 kg m−2) was obtained. From the assumptions of the applied technique, we can draw the inference that this erosion was caused by rains produced in the month prior to the date of soil sampling.

High variability of soil erosion and hydrological processes in Mediterranean hillslope vineyards (Montes de Málaga, Spain)

Conventional Mediterranean vineyards from the Montes de Málaga (Axarquía region, Spain) are characterized by high average temperatures, extreme rainfall events during autumn and winter, elevated stoniness and steep slopes (20–50°). Traditionally, several problems of high soil loss, rill and ephemeral gully generation, and elevated runoff are observed by farmers, which are increasing land degradation processes and a decrease of the productivity.According to this, the main aims of this paper were: i) to quantify the initial soil loss, surface flow and infiltration processes; ii) to characterize and describe the hydrological and geomorphological dynamics; iii) to detect the key factors, which control the soil erosion processes.For this purpose, a combined methodology was applied, using soil analysis, a small portable rainfall simulator and a Guelph permeameter on one experimental plot cultivated with vineyards with steep slopes. Results showed a high variability of soil erosion and permeability processes. Soil analysis showed an elevated concentration of silt particles and stoniness, with higher contents of sand particles between 0 and 5cm, and clays from 5cm. With a Guelph permeameter, high average of permeability and saturated hydraulic conductivity with elevated standard deviation were observed. Furthermore, an increase of these parameters from the upper to the foot slope was registered. By using rainfall simulations, on the upper and the foot slope positions the highest runoff coefficient and soil loss were registered. The most elevated peak of sediment concentration was obtained on the middle slope. In general, high infiltration coefficients between 66.5 and 100% were observed.In conclusion it was observed that the activation of the soil erosion processes was due to the distribution of the surface soil components (high roughness, several cracks and high stoniness and silt content), the steep slopes and the impact of the soil traditional tillage practices. These Mediterranean hillslope vineyards registered a mixed Hortonian-Hewlettian model, which combines surface and sub-surface flow conditioned by the micro-topographical changes and its saturation degree.

First use of the 137Cs technique in Nigeria for estimating medium-term soil redistribution rates on cultivated farmland

Abstract Soil erosion is a serious problem in the forest-savanna transition zone or derived savanna of West Africa and Nigeria and needs to be reduced to maintain soil quality and to ensure food security. In 2007, the use of the fallout radionuclide 137 Cs as a tracer for estimating the magnitude of medium-term (40–50 years) rates of soil redistribution was tested at a research station in Ibadan, Nigeria, to investigate, for the first time, its applicability in the derived savanna of West Africa. Because of the traditional tillage practice for cassava cultivation of creating downslope oriented ridges and furrows during the annual ploughing, there was a need to adapt the 137 Cs approach to these specific condition. The mean inventory was determined for cores collected from both ridges and furrows at different positions down the slope and this value was used to estimate the downslope variation in the longer term soil redistribution rate. The mean 137 Cs reference inventory obtained for an undisturbed site was 568 ± 138 Bq m −2 . The average inventory for the upper slope of the cassava field (423 ± 323 Bq m −2 ) was generally lower than the average inventory for the middle slope (509 ± 166 Bq m −2 ) and for the lower slope (606 ± 245 Bq m −2 ) and these results provided clear evidence of the downslope movement of soil. The mean 137 Cs inventory for the study area within the cassava field (496 ± 273 Bq m −2 ) was 13% lower than the reference inventory, indicating that some of the soil mobilised and redistributed by erosion had been exported beyond the field. Using 137 Cs data set and the conversion model mass balance model 2 (MBM2), the gross erosion rate from the cultivated site was estimated to be 18.3 t ha −1 year −1 and the net erosion rate 14.4 t ha −1 year −1 , providing a sediment delivery ratio of 78%. These estimates are comparable to the rates generated by conventional soil loss measurements made close to the study site. The study demonstrates that the 137 Cs technique can be successfully used to obtain data on medium-term soil redistribution in the derived savanna of Nigeria, and that it could be a useful tool for supporting the improvement of soil conservation on farmland in West Africa.

Modelling field scale water partitioning using on-site observations in sub-Saharan rainfed agriculture

Abstract. Smallholder rainfed farming systems generally realise sub-optimal crop yields which are largely attributed to dry spell occurrences during crop growth stages. However, through the introduction of appropriate farming practices, it is possible to substantially increase yield levels even with little and highly variable rainfall. The presented results follow research conducted in the Makanya catchment in northern Tanzania where gross rainfall amounts to less than 400 mm/season which is insufficient to support staple food crops (e.g. maize). The yields from farming system innovations (SIs), which are basically alternative cultivation techniques, are compared against traditional farming practices. The SIs tested in this research are runoff harvesting used in combination with in-field trenches and soil bunds (fanya juus). These SIs aim to reduce soil and nutrient loss from the field and, more importantly, promote in-field infiltration and water retention. Water balance components have been observed in order to study water partitioning processes for the "with" and "without" SI scenarios. Based on rainfall, soil evaporation, transpiration, runoff and soil moisture measurements, a water balance model has been developed to simulate soil moisture variations over the growing season. Simulation results show that, during the field trials, the average productive transpiration flow ranged between 1.1–1.4 mm d−1 in the trial plots compared to 0.7–1.0 mm d−1 under traditional tillage practice. Productive transpiration processes accounted for 23–29% while losses to deep percolation accounted for 33–48% of the available water. The field system has been successfully modelled using the spreadsheet-based water balance 1-D model. Conclusions from the research are that the SIs that were tested are effective in enhancing soil moisture retention at field scale and that diversions allow crop growth moisture conditions to be attained with early rains. From the partitioning analysis, it is also concluded that there is more scope for efficient utilisation of the diverted runoff water if storage structures could be installed to minimise runoff and deep percolation and, hence, regulate water flow to the root zone when required.

Impacts of traditional tillage practices on field characteristics and crop yields: the case of semi-arid, Central Tanzania

Impacts of traditional tillage practices on field characteristics and crop yields: the case of semi-arid, Central Tanzania

Traditional Tillage Systems as Drought Adaptation Strategies of Smallholder Farmers: The Case of Semi-Arid Central Tanzania

This article presents local knowledge on ecosystem management by analyzing and discussing traditional tillage practices applied by smallholder farmers as a response to drought risks in dryland areas of Mpwapwa District, central Tanzania. Farming activities in the area wholly depend on rain-fed systems. Information from key informants and in-depth household interviews indicate that farmers in this area use three different traditional tillage practices—no-till (sesa), shallow tillage (kutifua), and ridges (matuta). Available information suggests that selection of a particular practice depends on affordability (in terms of costs and labor requirements), perceived ability to retain nutrient and soil-water, and improvement of control of erosion and crop yield. In this area, smallholder farmers perceive no-till practice to contribute to more weed species, hence more weeding time and labor are needed than in the other two practices. The no-till practice also contributes to low soil fertility, low soil moisture retention, and poor crop yield. No plans have been made to introduce irrigation farming in these marginal areas of central Tanzania. Thus, improving the ability of the tillage practices to conserve soil moisture and maintain soil fertility nutrients using locally available materials are important tasks to be carried out. This will ensure the selection of practices that will have positive influence on improved crop yields in the area.

Tillage Practices and Their Impacts on Soil Fertility in Farmer' Fields in Semi-Arid Central Tanzania

We assessed impact of 5 years continuous application of traditional tillage practices (no-till (NT), shallow tillage (ST) and ridging tillage (RT)) applied by smallholder farmers in central Tanzania. Soil samples were collected at two different soil depths to verify farmer' perceptions. At 0–15 cm, ANOVA showed no significant difference (p > 0.05) for tested parameters except total N which was significantly different and rich in NT. Whereas no significant difference were observed for chemical properties analysed at 15–30 cm, percentage clay, silt and sand content were significantly different (p < 0.05) over tillage practices with NT having more silt and clay.