Infiltration Pits Research Articles

Evaluating effects of selected water conservation techniques and manure on sorghum yields and rainwater use efficiency in dry region of Zimbabwe

Sorghum production in semi-arid areas of Zimbabwe is constrained by low and erratic rainfall, low fertility and soil moisture stress. Sorghum grain yields ranges from 0.2 to 0.4 t ha−1 in sandy-to-sandy loam soils respectively. The objective of the study was to assess cattle manure and rainwater harvesting techniques in improving sorghum grain yield in a semi-arid region of Zimbabwe. The experiment used a randomised complete block design with rainwater harvesting technique as a main treatment factor at three levels. Sub-plot factor was cattle manure at five levels (0, 2.5, 5, 10 and 15 t ha−1) and two sorghum varieties (Macia and SV1) as sub-sub plot factor. Sorghum grain yields were improved significantly (p < 0.05) for both varieties using tied contours. Increasing application rates of cattle manure, showed significant increase (p < 0.05) in sorghum grain yield over the control (0 t ha−1). Tied contour had higher grain yield (1.15 t ha−1) with the use of Macia variety. Stover yield was highly influenced by rainwater harvesting method of tied contour (p < 0.05) compared with infiltration pit and standard contour. Increase in application levels of cattle manure show significant (p < 0.05) increase in stover yields. Tied contour had the highest (3.11 kg ha−1 mm−1) rainwater use efficiency which show significant differences (p < 0.05) from infiltration pits and standard contour. Interaction of tied contour and different rates of cattle manure showed significant increments in rainwater use efficiency with increases in manure application rates. Tied contours, 15 t ha−1 cattle manure and Macia variety are potential strategy to achieve climate smart agriculture and improve food security in semi-arid areas. Sorghum production in marginalised areas can be productive with adoption of tested techniques.

The effects of contour-based rainwater harvesting and integrated nutrient management on maize yields in semi-arid regions of Zimbabwe

In the smallholder farming areas located in semi-arid regions of Zimbabwe, low and unreliable rainfall distribution and poor soil fertility are the major factors limiting crop production. The negative effects of these biophysical factors have been worsened by climate change. However, the major challenges have been the lack of sustainable, low-cost water and nutrient management technologies for these semi-arid regions. The objectives of this study were to evaluate the effects of contour-based rainwater harvesting (RWH) namely tied contours (TC), infiltration pits (IP) which were compared with the standard contour (STDC), and intergrated nutrient management (INM) where cattle manure was used as basal fertiliser and Ammonium Nitrate (AN) as top dressing, on maize yields. Results showed that fields with RWH had higher yields compared to STDC. Average maize yields were 2210 and 1792 kg ha−1 for TC and IP which were 88% and 52% above STDC (1176 kg ha−1) respectively. Increasing nitrogen (N) levels resulted in a further increase in maize yields. Return on investment was negative during drier years and was significantly higher in RWH systems compared with STDC during wet seasons. Farmers need to reduce mineral fertiliser application during dry seasons since little rainwater is captured. We conclude that contour based RWH and INM can be used as sustainable low cost methods of crop production. Higher fertiliser application rates when rainfall is limiting, do not result in increased return on investiment.

Vsakovací zařízení na lesní dopravní síti a jejich funkčnost

The aim of this article is to present the basic theses about the function and potential of infiltration pits under culvert mouths on forest roads. The methodology consisted of a combination of literature review and own in situ experiments. Experimental verification was carried out on sections of forest roads on two training forest enterprises (TFE) at Kostelec nad Černými lesy and Masarykův les Křtiny (Czech Republic). At each location, two infiltration pits were built in a paired design with a uniform retention volume. One of the pits was always located under a pipe culvert. The control pit was located approx. 30 m far from it, in the same pedological and vegetation conditions without a centralized inflow. Measurements from the study period (autumn 2022) indicated that the infiltration pits under the culverts had unexpectedly low efficiency in retaining and infiltrating surface runoff. Mostly, due to the fact that in the analyzed period the surface runoff was minimal, even though precipitation did occur. During the study period, the infiltration pits did not reach the expected potential to support the hydric regime of the landscape.

Enhancing Sorghum bicolor (L.) grain yield with the use of field edge rainwater harvesting and NPK fertiliser in a dry region of Zimbabwe

AbstractBackgroundFarmers in marginalised areas across Africa are mainly resource poor and have limited capacity to procure enough inorganic fertilisers. This contributed immensely towards declining crop productivity causing food insecurity. Soil moisture stress is another key factor which has led to a decline in crop yields across semi‐arid areas. This experiment determines the effects of field edge rainwater harvesting and NPK fertiliser microdosing on sorghum grain yields and agronomic nutrient use efficiency of two sorghum varieties (Macia and SV1). Rainwater harvesting techniques was the main plot factor with three levels (tied contour, infiltration pits and standard contour), sorghum variety was used as subplot factor with two levels (Macia and SV1) and NPK fertiliser as sub‐sub plot factor with five levels (0, 25, 50, 100 and 150 kg ha−1) with all treatments replicated three times. A randomised complete block design arranged in split‐plot was used.ResultsPhosphorous was significantly increased from 3.32 to 3.52 mg kg−1 with no significant (p &gt; 0.05) increase in total nitrogen and soil organic carbon. Sorghum grain yields were statistically (p &lt; 0.05) influenced by main treatment factors. Tied contour had considerably higher grain yield (861 kg ha−1) than infiltration pits and standard contours. Highest grain yield of 909 kg ha−1 was observed from plots applied 150 kg ha−1 NPK fertiliser. Macia variety performed significantly (p &lt; 0.05) higher than SV1. Grain yields show significant (p &lt; 0.05) increase with increasing fertiliser levels. Interaction of tied contour + Macia+ 150 kg ha−1 NPK fertiliser had significant grain yields (1150 kg ha−1) compared to other treatments. Treatments applied NPK fertiliser show significant differences (p &lt; 0.05) than unfertilised plots. Agronomic nutrient use efficiencies were significantly higher (p &lt; 0.05) from all treatments applied 25 kg ha−1 NPK fertiliser. Sorghum variety Macia had better nutrient use efficiency than SV1 in 2017/18 and 2018/19 seasons except during 2019/20 where results show insignificant differences.ConclusionIt can be concluded that farmers adopt the use of tied contour and Macia variety using 150 kg ha−1 to achieved higher yields. Combining rainwater harvesting method of tied contour and mineral fertiliser can increase sorghum grain yields in dry regions.

Evaluation of different rainwater harvesting techniques for improved maize productivity in semi‐arid regions of Zimbabwe with sandy soils

AbstractBackgroundMaize production in semi‐arid areas has been hindered by moisture stress and poor soil fertility. Long frequent droughts and shortening of growing seasons have been causing yield reduction. Limited knowledge of soil water management by farmers is another key contributor to poor maize yields in the smallholder sector. Therefore, the objective of the study was to investigate the effects of contour‐based and field‐based water harvesting technologies on maize grain yield and rainwater use efficiency under rain‐fed conditions on three farms (Jera, Kudzeeta and Manjengwa) with sandy soils in the Marange smallholder farming area of Zimbabwe. The experiment was laid out as a split plot in a randomised complete block design with three replications at each site. Contour‐based rainwater harvesting structures were the main treatments comprising tied contour (TC), standard contour (STDC) and infiltration pits (IP). Field‐based rainwater harvesting structures were the subplot treatments comprising tied ridges (TR), pot holing (PH) and the flat system (FLAT).ResultsResults showed that the contour‐based water harvesting structures significantly influenced (p &lt; 0.05) maize grain yields. TCs had the highest maize grain yields compared with infiltration pits and STDCs over two cropping seasons. Maize yields on field‐based TR were significantly higher (p &lt; 0.05) than on the FLAT but were not different (p &gt; 0.05) with what was obtained on PH. The combination of TC and TR water harvesting technologies resulted in significantly higher maize yields (p &lt; 0.05) than other combinations. TR and STDC also gave higher maize grain yield at Jera farm which was significantly different from other two farms. Rainwater use efficiency followed the same trend as maize grain yields, with TC having higher values but not significantly different (p &gt; 0.05) from STDC.ConclusionIt can be concluded that farmers in semi‐arid areas adopt a combination of TC with either TR or PH to improve rainwater use efficiency and maize yields.

Augmenting Leucaena leucocephala biomass with mineral fertiliser on rainwater use efficiency, agronomic efficiency and yields on sorghum (Sorghum bicolor [(L.) Moench]) under rainwater harvesting techniques in semi-arid region of Zimbabwe

Food security in semi-arid regions is threatened by declining soil fertility, soil moisture stress and long frequent droughts as a result of erratic rainfall. Therefore we assessed the effects of augmenting Leucaena leucocephala biomass (organic manure) with mineral fertiliser on rainwater use efficiency, agronomic efficiency, grain and stover yields for two sorghum varieties (Macia and SV1) under rainwater harvesting techniques. The experiment was laid in split-split plot arrangement with rainwater harvesting method as main plot factor, with Leucaena biomass + NPK fertiliser as subplot factor and sorghum variety as sub-sub plot factor over three cropping seasons. Data collected include rainwater use efficiency, agronomic efficiency, grain and stover yields. Results show that tied contours have significantly (p ≤ 0.05) higher grain and stover yields from all varieties and seasons. Irregardless of sorghum variety, tied contours had significant (p ≤ 0.05) sorghum grain and stover yield followed by infiltration pits and lastly standard contours. Grain and stover yields improved with increasing levels of Leucaena biomass + NPK fertiliser combination. Highest grain yields observed were 1.146 t ha−1 (Macia) and 1.1 t ha−1 (SV1) from tied contour +15 t ha−1 biomass +150 kg ha−1 NPK fertiliser treatments. Rainwater use efficiency was significantly (p ≤ 0.05) higher from tied contours compared to infiltration pits and standard contour. Rainwater use efficiency was statistically (p ≤ 0.05) influenced by increasing application levels of Leucaena biomass + NPK fertiliser in all seasons. Agronomic efficiencies were considerably (p ≤ 0.05) affected by rainwater harvesting, Leucaena biomass + NPK fertiliser and interaction of all factors. It can therefore be concluded that Leucaena biomass + NPK fertiliser, tied contours and infiltration pits improve sorghum yields. Augmenting 2.5 t ha−1 biomass with 25 kg ha−1 NPK fertiliser under tied contours and Macia have better agronomic efficiency.

Compatibility of Leucaena leucocephala biomass and cattle manure combination under rainwater harvesting on sorghum (Sorghum bicolor (L.) Moench) productivity in semi-arid region of Zimbabwe

Soil infertility is one of the constraints contributing to poor sorghum production in semi-arid areas across Africa. To increase sorghum production, there is need to address soil fertility issues. Therefore, the objective was to assess the effects of Leucaena/cattle manure combination on grain and stover yields, harvest index and net return of two sorghum varieties (Macia and SV1) under rainwater harvesting techniques. The field experiment was conducted as a randomized complete block design over three cropping seasons in a split-split plot arrangement. Results show significant (P < 0.05) increase in sorghum grain yield with increased applications of Leucaena/cattle manure combination. Macia variety had statistically greater (P < 0.05) grain yield than SV1 variety. Tied contour show considerably higher yield for both varieties across all seasons. Stover yield show significant differences (P < 0.05) as affected by Leucaena/cattle manure and rainwater harvesting techniques. Rainwater harvesting techniques significantly influence (P < 0.05) harvest index, with tied contour and infiltration pits having comparably higher harvest index than standard contour. Application of Leucaena/cattle manure combination show significant increases in harvest index with increased application rates. However, no significant effect was observed at 20 and 30 t ha−1 from SV1 variety across all seasons. Leucaena/cattle manure combination significantly influenced (P < 0.05) sorghum net return across all seasons except at 5 t ha−1 where no significant effect was observed. Macia variety had higher net return than SV1. To increase grain yield and net return, farmers can adopt Macia variety, tied contour and 10 t ha−1 Leucaena/cattle manure combination due to higher incremental yield per tonne.

Rainwater harvesting and Leucaena leucocephala biomass rates effects on soil moisture, water use efficiency and Sorghum bicolor [(L.) Moench] productivity in a semi-arid area in Zimbabwe.

Sorghum is one of the major staple crops in Sub Saharan Africa but its production is mainly limited by moisture stress, frequent droughts and soil infertility, especially in the smallholder farming systems. This raises the need to develop climate smart options to improve sorghum production. The objective was to assess the effects of rainwater harvesting and use of different Leucaena leucocephala biomass rates on soil moisture content, rainwater use efficiency, and stover and grain yields in two sorghum varieties (Macia and SV1). The experiment was laid as a randomized complete block design in split-split plot arrangement from 2017/2018 to 2019/2020 season. The results show that tied contour (TC) and infiltration pits (IPs) significantly (P < 0.05) increased soil moisture content than standard contour (SC). Soil moisture content increased gradually with the increase in soil depth (20-40 cm > 0-20 cm), with 2018/2019 season having the maximum soil moisture content. Soil moisture content also increased with the increase in application rates of Leucaena biomass. Grain and stover yields were significantly (P < 0.05) increased by all Leucaena biomass application rates with higher yield observed in 2018/2019 season. SC had significantly lower grain and stover yields at all Leucaena biomass application rates. TC and IPs had comparable rainwater use efficiency compared to SC. Rainwater use efficiency increased with application rates of Leucaena biomass across all seasons and varieties. TC and IPs are better adaptive mechanisms against drought spells in semi-arid areas and can be combined with 10 t ha-1 of Leucaena biomass due to better yield increments realized. © 2022 Society of Chemical Industry.

Field edge rainwater harvesting and inorganic fertilizers for improved sorghum (Sorghum bicolor L.) yields in semi-arid farming regions of Marange, Zimbabwe

Sorghum (Sorghum bicolor L.) is mainly cultivated in marginal areas of Zimbabwe, where soil fertility is poor and rainfall is low, erratic, and poorly distributed, leading to low yields. The study aimed to determine the effect of tied contour (TC) and in-contour infiltration pits (IP) rainwater harvesting (RWH) methods and varying nitrogen fertilizer application rates on the yield of two sorghum varieties, Macia and Sc Sila. A split-split plot experiment was laid out, with the main plot factor being the RWH method, the subplot factor being sorghum variety, the sub-sub plot factor being nitrogen application, and the sub-sub-sub plot factor being the plant distance from the RWH method. The experiment was done at Mt Zonwe's small-scale farming community in the Mutare region from 2016/17 to 2018/19. The results revealed that TC and IP increased the gravimetric water content (gwc) of the soil. The gwc decreased gradually as the distance from the rainwater RWH method increased (0–5 m > 5–10 m > 10–15 m), with the 2016/17 season having the maximum gwc. In all seasons, TC and IP yielded much more sorghum grain than standard contour (SC). Sorghum grain production was significantly greater at all nitrogen application rates and consistently higher at all plant distances from the RWH method in the 2016/17 season with more rainfall. In comparison to TC and IP, the SC had significantly lower grain yield at all nitrogen application rates. At all plant distances from the RWH method, TC and IP had significantly higher grain production than SC in each variety of sorghum.

Effect of contour rainwater-harvesting and integrated nutrient management on sorghum grain yield in semi-arid farming environments of Zimbabwe

ABSTRACT The application of insufficient amounts of mineral fertiliser, coupled with unreliable precipitation, has caused a drastic reduction in the yield of sorghum in the smallholder-farming areas of Zimbabwe. This calls for innovative interventions to improve production under changing climatic conditions. This study evaluated the effect of contour-based rainwater-harvesting methods and the use of cattle manure + N nutrient amendment on sorghum yield. A split-split plot experiment was conducted where rainwater-harvesting practice, sorghum variety, cattle manure + N and distance from rainwater-harvesting structure were treatment factors. The results showed that the yield of sorghum was significantly higher under the tied contour and infiltration pits than standard contour at all distances from rainwater-harvesting practices and seasons. In all seasons sorghum varieties Macia and Sc Sila showed higher yield under the tied contour and infiltration pits than standard contour. However, regardless of the distance from rainwater-harvesting practice and season the sorghum variety, Macia showed a higher grain yield than Sc Sila. At each incremental level of N application to cattle manure, Macia had a higher grain yield than Sc Sila, and no significant grain yield benefits were shown in each variety at N application to cattle manure above 50 kg N ha−1.

Supporting Growth and Transpiration of Newly Planted Street Trees With Passive Irrigation Systems

AbstractSolutions that use stormwater runoff to rapidly establish tree canopy cover in cities have received significant attention. Passive irrigation systems that direct stormwater to trees have the potential to increase growth and transpiration and may limit drought stress. However, little data from the field demonstrates this, and we lack robust and reliable designs which achieve it. Here, we quantified growth and transpiration for trees: (a) in infiltration pits receiving stormwater, with a raised underdrain and internal water storage (drained), (b) next to infiltration pits receiving stormwater but without an underdrain and internal water storage (adjacent), and (c) planted in standard pits, not receiving stormwater (control). Trees in drained pits grew twice as fast as control trees in the first 2 years, but fast initial growth rates were not sustained in years three and four. Trees outgrowing the small infiltration pits, rather than a lack of water, was most likely responsible for growth rates slowing down. Despite this, rapid initial growth for trees in drained pits meant trees were larger by year three and transpired more than twice as much (5.1 L d−1) as trees adjacent to pits (2.4 L d−1) or control trees (2.3 L d−1). No trees showed drought stress during the study. However, some trees planted adjacent to infiltration pits showed waterlogging stress, suggesting caution installing infiltration pits adjacent to establishing trees in fine‐textured soils. Overall, our results suggest passive irrigation systems can substantially increase initial tree growth, thereby facilitating greater cooling and runoff reduction through increased transpiration.

Assessment of groundwater drought vulnerability and delineation of sites for artificial recharge – a case study

Drought impacts both surface water and groundwater, which leads to reduced supply. Groundwater drought indicates continuous depletion of groundwater level, storage and discharge. Assessment of groundwater drought conditions is necessary for effective planning of drought management strategies. In this study, the drought vulnerability of Chittur Block in Palakkad, Kerala is assessed by the occurrence of groundwater drought and is mapped using geographic information system (GIS). A strategy for the effective implementation of artificial recharge schemes is proposed to combat future drought conditions. A combination of GIS and weighted parameter approach (WPA) is employed to delineate safe, suitable locations for artificial groundwater recharge. Site specific recharging structures such as check dams, infiltration pits, injection wells and percolation ponds are recommended within the 65% area which was identified as most conducive for artificial recharge.

Integrated Water Resource Management: Rethinking the Contribution of Rainwater Harvesting

Rainwater harvesting (RWH) is generally perceived as a promising cost-effective alternative water resource for potable and non-potable uses (water augmentation) and for reducing flood risks. The performance of RWH systems has been evaluated for various purposes over the past few decades. These systems certainly provide economic, environmental, and technological benefits of water uses. However, regarding RWH just as an effective alternative water supply to deal with the water scarcity is a mistake. The present communication advocates for a systematic RWH and partial infiltration wherever and whenever rain falls. By doing so, the detrimental effects of flooding are reduced, groundwater is recharged, water for agriculture and livestock is stored, and conventional water sources are saved. In other words, RWH should be at the heart of water management worldwide. The realization of this goal is easy even under low-resource situations, as infiltration pits and small dams can be constructed with local skills and materials.

Dead level contour technical design parameters required for sustainable crop production in semi-arid areas of Zimbabwe

Smallholder farmers in sub-Saharan Africa are increasingly exposed to risks such as erratic rainfall, prolonged dry spells, and frequent droughts that threaten sustainable crop production. This study assessed the effectiveness of dead level contours with innovations (DLC INN), dead level contours with infiltration pits (DLC INFIL), dead level contours with open channels (DLC OPEN) and standard graded contours (SGCs) in harvesting and storing water in the channel, and improving crop conditions during the critical stages of maize growth on different soil textural groups in the Zvishavane District of Zimbabwe. The DLC INFIL, DLC OPEN and DLC INN outperformed the SGC under medium- and heavy-textured soils, with yields ranging between 1.7 and 2.36 t/ha compared to 0.9 t/ha for the SGC. For light textured soils, the DLC INN had the highest maize yield, averaging 0.8 t/ha. On heavy textured soils using DLC INN, DLC INFIL and DLC OPEN, smallholder farmers may use a spacing interval of 24–27 m. On medium textured soils, DLC INN and DLC INFIL can be used at a spacing interval of 18–21 m and 12 to 15 m with DLC OPEN. On light textured soils, farmers are advised to invest in DLC INN only, using a spacing interval of 12–15 m.

Identification of suitable sites and structures for artificial groundwater recharge for sustainable water resources management in Vamanapuram River Basin, South India

Sustainable groundwater management by artificial recharge of aquifers has become a possible resolution for increasing depletion and deterioration of groundwater in several river basins across the word. The present study identifies suitable sites to adopt possible aquifer recharge structures in the Vamanapuram River Basin (VRB), South India, where water scarcity and groundwater declines caused parts of the basin to fall in the semi-critical category. The potential of the basin for suitable artificial recharge were investigated by analysing the geo-environmental variables using remote sensing, geographical information system and analytic hierarchy process (AHP) technique. The geo-environmental variables considered for the analysis includes plan curvature, profile curvature, land use/land cover, aspect, distance from streams, relative relief, geology, geomorphology, slope angle, available space for recharge, lineament density, sand percent, rainfall and drainage density. The slope stability assessment and potential recharge zonation was carried out using weighted overlay analysis by assigning the comparative weights to different thematic layers with the help of the multi-criteria decision-making tool of AHP technique. The results of the slope stability analysis were validated using existing slope failure data. The receiver operating characteristic curve (ROC) and area under the curve (AUC) value were used as a performance indicator for the validation of slope stability map. Further, suitable locations in the basin for four site-specific recharging mechanisms viz., rainwater infiltration pits, percolation ponds, injection wells and pond-cum-injection wells were identified using a rule-based approach. It is estimated that an annual volume of 2489.3 Mm3 of water is available to recharge groundwater in VRB, which accounts for nearly 19.2% of the precipitation in the basin. The potential for artificial recharge in VRB is found to be controlled significantly by factors such as geology, geomorphology, slope and available space for recharge. The slope stability analysis shows that about 94.3% of the basin fall under stable zone category and are safe for the construction of aquifer recharge structures, which was further validated with a prediction accuracy of 89.2%. It is estimated that 22,17,639.76 (m3/year) volume of water is available for recharge in VRB; however, the average recharge rates in the basin varies spatially. Western and north-central parts of the basin are found to be suitable for the construction of rainwater infiltration pits and injection wells and percolation ponds respectively, whereas the central parts are found to be suitable for the implementation of percolation ponds and pond-cum injection wells. The outcome of this study can be used for the planning of sustainable groundwater development and regional management of the river basin.

Effects of Fertilizer Micro-dose and In Situ Rain Water Harvesting Technologies on Growth and Yield of Pearl Millet in a Semi-arid Environment

Declining soil fertility and low rainfall are key constraints to crop production and are threatening food security in semi-arid areas. Applying inorganic fertilizer at reduced amount (micro-dose) and in situ rainwater harvesting using infiltration pits (IP) or tied ridges (TR) are low-input strategies to cope with these constraints. This work investigates the effect of integrating fertilizer with in situ rainwater harvesting technologies on pearl millet growth, yield and household profitability among Tanzanian smallholder farming communities. Split plot field experiments were conducted from 2015 to 2017 cropping seasons. Flat cultivation (FC) with zero fertilizer application resulted in lowest grain yield ranging from 297 to 453 kg/ha and in a negative net profit (NP). The highest yield of 2202 kg/ha was obtained upon the use of recommended rate under IP, but it resulted in negative NP. Infiltration pits under 25% micro-dose resulted in relative higher grain yield (778–2202 kg/ha) compared to TR (887–1915 kg/ha) and FC (592–1144 kg/ha); despite higher yield, it resulted in negative NP. Tied ridges and FC with micro-dose at 25% of recommended rate had a yield advantage ranging from 537 to 959 kg/ha and 295 to 455 kg/ha, respectively, compared to farmer practices, and both resulted in positive NP. The use of micro-dose at 25% of recommended rate along with TR or FC which gave higher grain yield and NP compared to farmers practice is recommended to resource-poor farmers for improved pearl millet productivity.

Turning Volcanic Ash into Fertile Soil: Farmers’ Options in Coffee Agroforestry After the 2014 Mount Kelud Eruption

Post eruption land reclamation consists of hoeing, mixing volcanic ash with soil, adding external organic and/or in-organic fertilizers and making infiltration-pits (‘rorak’). This study, after the 2014 eruption of Kelud volcano, aimed to evaluate: (a) soil physico-chemical fertility post eruption, (b) impact of organic inputs interacting with ash in infiltration pits on soil C and N underneath (1 st experiment), (c) biomass loss (decomposition) of local biomass ( Trema orientalis and Parasponia andersonii ) in a coffee agroforestry system (2 nd experiment). Measurements in the ash-affected (+Ash) Tulungrejo-village (Ngantang-Malang district) were contrasted with an area without recent ash deposits (-Ash) in Krisik (Gandusari-Wlingi district). The 1 st experiment (-Ash site) treatments did not lead to statistically significant influences on soil conditions just below the infiltration pits during 12 weeks of monitoring. The 2 nd experiment quantified rate of biomass loss from litterbags. In +Ash location, litter half-life time (t 50 ) was 19.5 weeks for coffee or Parasponia as single biomass source to 24 weeks for Coffee+Sengon+Durian. In -Ash location decomposition was slower, with t 50 of 24 weeks for Parasponia to 27 weeks for Coffee+Sengon+Durian biomass. Concentrations of soil NH 4 and NO 3 below the litterbags peaked between 4 to 8 weeks, with nitrification lagging behind on ammonium release.

Effect of runoff management and soil conservation practices on the growth and yield of Maize (Zea mays) in a sub-humid agro-climatic zone of Ile-Ife, Nigeria

Field experiments were conducted at the Teaching and Research Farms, Obafemi Awolowo University, Ile-Ife in a completely randomized design with five soil-water conservation (SWC) treatments: Contour bunds (CT); Infiltration pits (IP); Mulched plots (ML); Tied ridges (TR); and the Conventional practice (CP), which served as the control. Four (4) levels of soil moisture replenishment [50% (Full Replenishment), 25% (½), 12.5 % (¼), and 6.25 % (1/8)] after depletion to 50% of Field Capacity (FC) were considered as supplementary water application from an in-situ RWH system. Measurements of soil moisture in the soil profile, plant growth parameters and yield at harvest were made. Results showed that maize yield and WUE varied amongst the SWC practices and within the years from the experimental plots with substantial yield improvements. The TR and CT gave better yields compared with the ML and IP of the same year. The 50 and 25% replenishment levels under TR and CT also gave better yield and WUE compared with other levels of replenishment. Biomass yield for the 2008-2010 planting seasons recorded higher values in TR, IP and CT compare to the control experiment, while the moisture retention ability was better in TR and slightly lower in CT of the same year. In 2011 soil moisture replenishment, the 50% gave the highest yield in a TR, followed by the CT and ML treatments. The TR gave the best WUE for the 50% and in all cases the CP gave a comparatively low efficiency. The study concluded that the methods of soil moisture conservation practice is an effective way to increase water availability for higher crop yields; but a combination of the supplementary, in-situ RWH system could produce better results in terms of enhanced yield and mitigate against the adverse effect of short duration intra-seasonal drought.

Women Farmers Use of Indigenous Knowledge in Land and Water Management for Climate Change Adaptation in Flood-Plain Agricultural Areas of Imo State, Nigeria

This study was carried out to analyze indigenous knowledge practices employed by women farmers for climate change adaptation and mitigation in Imo State, Nigeria. A total of 360 women farmers was randomly selected from 7 flood plain areas of the State. Questionnaire and oral interview were used to elicit information from the respondents. Percentages, mean and standard deviation were used to analyze data collected. Results showed the indigenous land and water management practices to include ; mulching (88.8%), use of mounds (80.5%), crop rotation (97.2%), soil fertilization (81.6%), conservation agriculture (97.2%), construction of infiltration pits (83.3%), construction of wells and basins for water storage (94.4%), terrace building (96.9%), planting mangrove trees (92.7%), use of sand bags against erosion (96.6%) among others. The high mean (M) response below showed the benefits of use of indigenous knowledge in land and water management to include; enhanced agricultural productivity (M=3.64), reduced water stress (M=3.25), improve soil air and water quality (M=2.86), improves soil organic matter content (M=2.95), increase soil moisture content (M=2.90), reduces erosion menace in farm (M=2.92) and others. The following challenges were faced – high transaction cost (M=3.04), land tenure problems (M=3.95), insecurity of rights to land (M=3.35), low level of income (M=3.67), lack of education and training (M=3.55) among other challenges. Extension training of women farmers be vigorously pursued to educate and enlighten the rural agricultural population.

Adoption of Water Conservation Technologies among Small Scale Farmers in Lwengo District – Uganda

This study identified and characterised the dominant water conservation technologies (WCT) employed by small scale farmers in Malongo and Kyazanga sub-counties in Lwengo district. It employed a cross sectional household survey design, using systematic sampling to obtain 380 household samples. A quantitative analysis, Multiple Correspondence Analysis (MCA) and Logit regression model were used to analyse these data to identify and characterise the dominant WCT and establish the most significant factor affecting the adoption of the technologies. Results indicated that mulching was the most dominant WCT employed, followed by Valley dams/reservoirs, terracing, tied ridges, deep tillage and infiltration pits. The Logit model indicated that out of seven factors, five had a significant positive influence namely: access to credit (1.3); farm slope location (0.7); farm size (0.4); access to agricultural inputs and investment subsidies (0.4); and level of income (0.2). One factor had a significant negative influence (engagement in other economic activities/off-farm employment activities) and only one was found to be insignificant (access to market). It is recommended that the significant water conservation techniques be upscaled, and that emphasis also be placed on the most significant factors in order to strengthen the adoption of water conservation in the area.