Climate change effects on crop production in Yatta sub-county: farmer perceptions and adaptation strategies

In Yatta sub-County, a semi-arid land, there is scanty information on the causes and effects of climate change, as well as agricultural adaptation strategies. This scanty information assessment of climate related risks, and decision making about appropriate adaptation measures. A survey was conducted in two wards of Yatta, Kenya, to identify opportunities for building farmer capacity in dealing with climate variability. A semistructured questionnaire was administered to 60 households randomly distributed in the two wards and data was analyzed using Statistical Package for Social Scientists (SPSS). Results showed that farmers in the region were aware of climate change (98%) with the known indicators reported to be erratic and low rainfall (50%), drought (33%), and rising temperatures (14%). Farmers mentioned deforestation (73%) as the main cause of climate change, and reported major impacts on crop production in the region, such as the introduction of drought tolerant crops (45%) reduced yields (43%) and changes in planting time (38%). As a result, farmers prepared the land early using organic and inorganic fertilizers, planted early-maturing crop varieties and carried out water and soil conservation practices. Even though farmers in Yatta sub–county are aware of climate change its impacts and different coping and adaptation strategies, crop production in the region continues to decline. There is need, therefore, to increase farmer’s capacity to better adapt to the effects of climate change to ensure sustainable agricultural production and improved food security.Keywords: Agricultural production; Climate Change; Arid and Semi-Arid Lands; Adaptation to climate chang

Combined Effects of Legumes with Phosphorus Fertilizer on Nutrient Balances and Gross Margins in Maize (Zea mays L.) systems of Kabete sub-County, Kenya

Calculation of soil nutrient balances and gross margins (GM) is imperative in ascertaining effect of innovative technologies on soil fertility and farm profitability. A field experiment to evaluate effect of combined legumes and phosphorus fertilizer on soil N, P and K balances and crop GM in maize (Zea mays L.) systems was set up in Kabete Division, Kenya, in the long and short rainy seasons of 2012. The experimental set up was a randomized complete block design (RCBD) with a split plot arrangement. The main plots comprised cropping systems; (i) monocropping (sole maize), (ii) intercropping [white lupin (Lupinus albus L.)/maize (L/M) and chickpea (Cicer arietinum L.)/maize (CP/M)], and (iii) rotation [white lupin-maize (L-M) and chickpea-maize (CP-M)]. The split plots were phosphorus (P) fertilizers; Minjingu phosphate rock (MPR) and triple superphosphate (TSP), and (iii) no P fertilizer applied (CTRL). Soil N, P and K balances and gross margins were analyzed at plot level using NUTrient MONitoring (NUTMON - now known as MonQi) Tool box. Nutrient balances were negative across cropping systems and P sources except for K in M/CP (CTRL and TSP) intercrop. Significantly less negative N balances were obtained in maize monocrop (MPR), CP/M (CTRL) intercrop, CP-M (TSP) rotation, and L/M (MPR) intercrop. L/M (CTRL and TSP) intercrop and L-M (CTRL and TSP) rotation recorded more negative (highest losses) N balances. Across P sources, the maize monocrop, M/L intercrop and L-M rotation had significantly more negative P balances, than CP-M rotation and M/CP intercrop. P balances, across P fertilizers, were significantly less negative in M/CP compared to M/L intercrop. Less negative P balances were recorded in CTRL treatment compared to TSP and MPR across cropping systems. M/L (CTRL and TSP) intercrop system had pronounced negative K balances. In the rotation systems, significantly less negative balances were observed when maize was rotated with chickpea compared to lupin across all P sources. Pronounced GMs were realized in M/L intercrop (TSP) followed by L-M (TSP) and lowest in M/L (TSP and CTRL). The N, P and K nutrient balances in response to P sources and cropping systems exhibited a negative relationship with crop GM. The positive GMs obtained were thus at the expense of soil nutrient mining as treatments with high nutrient losses, case for N and P, had the highest GMs. Considering nutrient balance studies alongside economic analysis has thus demonstrated the hidden environmental costs in the positive crop GMs and by extension the efficiency of such production systems. As a result, increased GMs under introduced technologies are not sustainable unless the same is matched with adequate nutrient replenishments to balance those lost through harvested products and other nutrient loss pathways. Farmers would, actually, go for those technologies that not only maximize yields but also accrue high profits. In the context of this study, and in order of GM (from highest) analysis, M/L intercrop, maize monocrop and L-M rotation with application of TSP are such technologies. In the long-run however these technologies will prove untenable due to nutrient mining. Nonetheless to guarantee efficient production and sustainable maize systems, following application of P fertilizer and legume integration, it is important that profits accrued from farm sales be used to purchase fertilizers and/or support practices geared towards replenishing mined soil nutrients. This way farm profits realized will not be at the expense of nutrient mining. Keywords: Cropping systems; gross margins; Kabete sub-County; MonQi; Nutrient Balances; Rock phosphates

Genomic diversity and characterization of lungwoms

Analysis of the genetic diversity of organisms plays an important role in research of related species and clinical applications. Lungworms (Dictyocaulus spp) have been identified in many species of ruminants. This study aimed to investigate the genomic variations of lungworms species, which could potentially lead to practical control methods and therapeutics in the distinct species of lungworms. To determine genetic relatedness, lungworm DNA was isolated from white-tailed deer (Odocoileus virginianus), New Zealand Red deer (Cervus elaphus), Louisiana cattle (Bos taurus), Mississippi cattle, and Wisconsin cattle and extracted, amplified through polymerase chain reaction (PCR), and then visualized using agarose gel electrophoresis. Currently, the PCR protocol has been unreliable and protocols are being designed to give more consistent results. At the moment, different approaches are being used to get the PCR to run and be able to get consistent results when amplifying. Once the PCR is fully functional, the next steps will be DNA cloning and sequencing for further investigation of the different species.https://openriver.winona.edu/urc2019/1005/thumbnail.jp

CARBON STOCKS AND STOCK CHANGES IN AGROFORESTRY PRACTICES: A REVIEW

Trees on farmlands and agricultural lands play a crucial role in small holder farmers’ livelihoods in addition to carbon regulation through carbon sequestration. These trees have received much attention recently due to their contribution to climate change mitigation through carbon storage. Quantification of carbon stocks in these trees has always proven difficult due to the spatial extent of these trees and methodological difficulties encountered during measurement. This paper reviews a number of studies done in quantification of biomass and soil carbon stocks in agroforestry within tropics. Most appropriate method employed in determination of carbon stock changes is through use of allometric equations. The equations use parameters like diameter at breast height (DBH), height, crown area which can be measured during field inventory. DBH has always proven to be the best parameter to be used in the equation since it is easy to measure and it does not need expensive equipments.  Apart from trees, soils in agricultural lands have the capacity to store carbon and help mitigate effects of climate change. It then identifies the gap that future research can be done for accurate carbon quantification

Soil Organic Carbon Stocks as Influenced by Topography and Vegetation Cover Types at Different Soil Depths

Data on soil organic carbon stock in wooded grassland is important for assessing its contribution towards offsetting greenhouse gas emissions through carbon sequestration. Understanding the effect of topography and vegetation cover types on soil organic carbon stocks is therefore essential for adopting suitable strategies for reducing greenhouse gases emissions but little has been done to ascertain this. This study was conducted during the long (LRS) and short rainy seasons (SRS) of 2016 in Ilmotiok to determine the effects of topography and vegetation cover at different depths in the wooded grasslands of Laikipia County, Kenya. Randomized completely block design was used; the main plot was topographical zones (TZ); mid slopes (MS), foot slope (FS), toe slope (TS) and subplots vegetation cover (VC); tree (T), grass (G), bare (B). Soil samples were collected to a depth of 50 cm at an interval of 10 cm using soil auger. The samples were analyzed for texture, bulk density (BD) and soil organic carbon. The bulk density was highest under FS*B at 0-10 cm with a mean of (0.88gcm-3 and 0.97 gcm-3) for LRS and SRS respectively as compared to other TZ. The lowest bulk density was observed for MS*GR at 0-10 cm (0.78 gcm-3 SRS and 0.86 gcm-3 LRS) in comparison to the other VC. Highest SOC concentration (1.21 MgHa-1 and 1.10 MgHa-1) was recorded under TS*G at 0-10 as compared to 40-50 (0.52 MgHa-1 and 0.40 MgHa-1) whereas the lowest (0.92 MgHa-1 and 0.91 MgHa-1) was recorded on MS*B at 0-10 cm and 0.39 MgHa-1 and 0.28 MgHa-1 and at 40-50 for the LRS and SRS respectively. The same trend was observed for SOCs highest (9.72 MgHa-1 and 9.90 MgHa-1) for TS*G at 0-10 cm and (5.11 MgHa-1 and 5.66 MgHa-1) at 40-50 cm and lowest under SU*B at 0-10 (7.66 and 7.11 MgHa-1.) and (3.19 and 2.60) MgHa-1 LRS and SRS respectively. The results from this study indicates that topography and vegetation cover of the wooded grassland has an influence on soil organic carbon stocks. Grass vegetation act as a sink to carbon stock therefore revegetation using grass is highly recommended

Effects of Tillage Practices, Cropping Systems and Organic Inputs on Soil Nutrient Content in Machakos County

Low use efficiencies of inorganic fertilizers coupled with their rising costs has diverted attention of farmers towards organic sources. A study was conducted in Yatta sub-county between October 2012 to February 2013 short rains and April-August 2013 long rainy seasons to evaluate the how tillage, cropping and organic inputs influenced soil nutrient status. A Randomized Complete Block Design with a split-split plot arrangement replicated three times was used. The main plots were tillage practices (TP): Split-plots comprised the cropping systems (CS) while split-split plots were organic inputs, plus the Control. The test crops were sorghum and sweet potatoes (Impomea batata) with Dolichos (Dolichos lablab) and chickpea (Cicer arietinum L.) added either as intercrops or in rotation. Soil was randomly sampled at 0-30cm depth at the onset of the experiment and at maturity of test crop for NPK and % OC analysis. Significant (P≤0.05) high level of K (1.91 Cmol/+kg), available P (51.45 ppm), Total N (0.19%) and OC (2.19%), in combined TR, intercrop sorghum/chickpea with application of MRP+FYM during SRS of 2012 compared to the other treatment combinations was observed. Comparing different organic inputs, tillage practices and cropping systems combined TR, intercrop of sorghum/chickpea and MRP+FYM and FYM increased the soil nutrients status. In conclusion, soil organic inputs such as MPR and FYM are viable alternatives to inorganic fertilizers for improving the soil nutrient status. The study therefore recommends incorporation of the organic inputs in combination with TR, intercropping with legumes in their cropping systems to improve soil health and resilience

Intermediate maturing soybean produce multiple benefits at 1:2 maize: soybean planting density

Open Access Journal; Published online: 15 Aug 2018A study was conducted to identify the most suitable intercropping arrangement in smallholder farms in Western Kenya. Biomass and N (nitrogen)-accumulation, N2 fixation and grain yield of maize and soybeans grown as intercrops at three planting densities were assessed. The study was conducted in four seasons. Three soybean varieties, Namsoy 4m, SC Squire and TGx1987-18F, were used in the experiment. Maize: soybean planting densities 1:1 (D1), 1:2 (D2), 1:3 (D3) as well as sole soybean (SS) and sole maize (SM) were tested. Higher biomass, N-accumulation, and N-fixed in the order 3.8 Mg ha-1, 260 kg ha-1 and 161 kg ha-1 respectively, were recorded in D3 with long maturing variety TGx1987-18F. Conversely, higher soybean grain yield < 2.4 Mg ha-1 was achieved by intermediate maturing SC Squire in D3. The highest maize yield in the intercrop was obtained in D1. N balance calculations indicated that planting TGx1987-18F resulted in an addition of 6 to 67 kg N ha-1, while SC Squire and Namsoy 4 m removed 3 to 89 kg N ha-1 when soybean grain was removed from the field. The differences in N balances between the intercrops depended on the N-fixed and the amount of N in harvested soybean and maize grain. Greater land equivalent ratio < 1.75 were obtained with SC Squire and Namsoy 4m in D2. We concluded that intermediate maturing soybean have multiple benefits for farmers in Western Kenya at 1:2 maize: soybean planting density provided that the practice is accompanied with good soil and crop management practices

Effects of Tillage Practices and Organic Cropping Systems on the Yield of Sorghum (sorghum bicolor L.) and Sweet Potato (Ipomoea batatas L) in Yatta Sub-County, Kenya

The study was conducted between October 2012 to February 2013 short rain season (SRS) and April 2013 to August 2013 long rain season (LRS) in semi-arid Yatta sub-county, to evaluate the influence of tillage practices, cropping systems and organic inputs on the yield of sorghum and sweet potato. A Randomized Complete Block Design with a split-split plot arrangement replicated thrice was used. The main plots were tillage practices (TP); Oxen plough (OP), tied ridges (TR) and furrows and ridges (FR). The Split-plots were cropping systems (CS); mono-cropping (MC), intercropping (IC), and crop rotation (CR) while split-split plots were organic inputs; Farm Yard manure (FYM), Minjingu Rock Phosphate (MRP), combined MRP and FYM (MRP+FYM) and the control. Test crops were sorghum and sweet potatoes with Dolichos (Dolichos lablab) and chickpea (Cicer arietinum L) either as intercrops or in rotation. Plant sampling was done by harvesting the grain and tuber and yield determined by weighing with a precision balance. The yields increased significantly (P≤0.05) with application of MRP+FYM of 16.37 and 1.38 t ha-1 for sweet potatoes and sorghum mono-crop, respectively under TR were observed. There was also significant (P≤0.05) yield increase of chickpea and dolichos under combined TR, IC of sorghum with chickpea (1.44 t ha-1) and dolichos (1.38 t ha-1) and with application of MRP+FYM during SRS of 2012. Improved yield of srghum and sweet potatoes were attained with the combined TR, MC and with application of MRP + FYM