Evaluation and Comparison of the Common Land Model and the Community Land Model by Using In Situ Soil Moisture Observations from the Soil Climate Analysis Network

Soil moisture is a key state variable in land surface processes. Since field measurements of soil moisture are generally sparse and remote sensing is limited in terms of observation depth, land surface model simulations are usually used to continuously obtain soil moisture data in time and space. Therefore, it is crucial to evaluate the performance of models that simulate soil moisture under various land surface conditions. In this work, we evaluated and compared two land surface models, the Common Land Model version 2014 (CoLM2014) and the Community Land Model Version 5 (CLM5), using in situ soil moisture observations from the Soil Climate Analysis Network (SCAN). The meteorological and soil attribute data used to drive the models were obtained from SCAN station observations, as were the soil moisture data used to validate the simulation results. The validation results revealed that the correlation coefficients between the simulations by CLM5 (0.38) and observations are generally higher than those by CoLM2014 (0.11), especially in shallow soil (0–0.1016 m). The simulation results by CoLM2014 have smaller bias than those by CLM5 . Both models could simulate diurnal and seasonal variations of soil moisture at seven sites, but we found a large bias, which may be due to the two models’ representation of infiltration and lateral flow processes. The bias of the simulated infiltration rate can affect the soil moisture simulation, and the lack of a lateral flow scheme can affect the models’ division of saturated and unsaturated areas within the soil column. The parameterization schemes in land surface models still need to be improved, especially for soil simulations at small scales.

Contribution of land use practices to GHGs in the Canadian Prairies crop sector

The global crop sector is estimated to contribute about 10.4% of global GHGs annually. The Canadian crop sector is assessed as adding about 6.5% to total national emissions. These estimates over report the impact of farming as they ignore the complex interaction of cropping with the environment and the role land use, land use change and forestry (LULUCF) play in sequestering carbon. This study quantifies the contribution of land use to GHG emissions and removals in the Canadian Prairies crop sector between 1985 and 2016. The modeling effort explores how different farming practices (i.e., conventional tillage (CT), minimum tillage (MT), zero tillage (ZT), summerfallow, crop rotations, and residue retention) and input usage rates (i.e., fertilizer and fuel) affect GHG emissions in different soil climate zones and provinces in the Prairies region. The adoption of sustainable practices led to an 80% decline in GHG emissions in the crop sector between 1985 and 2016. Since 2005, the baseline for Canada’s Paris commitment, sectoral emissions dropped 53%, more than is required to meet the 2030 target. Most promising, the crop sector was a net GHG sink between 2013 and 2016 in Alberta and between 2006 and 2016 in Saskatchewan. As positive as these developments have been, more can be done by directing research to identify options for reducing GHGs in Manitoba (which made only minimal improvements as farmers there faced conditions requiring continuous use of conventional tillage practices), to explore better nitrogen management (a major continuing source of GHG from cropping) and by searching for low carbon transport options.

Prevalence and Distribution of Weed Flora in Some Major Sugarcane Growing Areas of Southern Guinea Savanna, Nigeria

Weed population survey was undertaken to determine prevalence and distribution of weeds, and asses weed flora shift in major sugarcane growing areas in Southern guinea savanna of Nigeria. The selected areas surveyed are namely Badeggi, Sulti, and Isenyi. The Sugarcane fields were assessed using 1.0 m x 1.0 m quadrat placed randomly at vegetative stage. Weed seedlings in each quadrat were clipped at the soil level and identified according to standards. Result revealed that a total of 38 weed species were recorded. Graminaea and compositae were most abundant and diversified families based on the number of species recorded. Individual weed species shows variation in their abundance, dominance and frequency. The most frequent weed species in the Sugarcane fields irrespective of the soil, climate and crop varieties were Hyptis suaveolens, Paspalum scrobiculata, Kyllinga squamulata, Dactylactenum aegypium and Cynadon dactylon and were considered as the most important species in the surveyed areas. From Similarity indices, variations were observed between locations. Accordingly, areas having similarity indices more than 60 % indicate similarities in weed community. Thus, when devising a weed control strategies same control option should be considered for the location that have similar weed flora and vise-versa.

Regeneration of Dead Bougainvillea Tree with Organic Manure

Bougainvillea is hard, woody climber tree, grow in high salt tolerant soil. The present study was carried out in regenerating Bougainvillea plant with organic manure. The research work was conducted at kitchen garden campus in January 2020. The collected soil samples of five trees species namely Pimple, Neem, Khejari and Rohira are mixed with 10kg fresh cow dung, 5kg cow urine, 2kg molasses & 2kg flour Kitchen wastes 10kg, Charcoal 10kg, Molasses 2kg, Rice 1kg, Humus 10kg, Wheat 10kg, Crashed sugar cane 10kg, Chicken manures 2kg, Wooden saw dust, Wooden chips & Rice lusts and mixed with water for preparing organic product. The organic product keeps for 3 days in open conditions. The prepared organic product was poured into the shoot and root. Later, the regrowth of the shoot and the root were reported in 4-5 months. The organic product enhanced the metabolism for regenerating permanent tissue and Meristematic tissue of Shoot horizon and root horizon. Later, The lateral branches and flower were emerged from the dead plant. The formulated organic product is competent to regrow dead plant. Keywords: Bougainvillea, Dead plant, organic manure, regeneration, soil, climate

Impact of urbanization trends on production of key staple crops

Urbanization has appropriated millions of hectares of cropland, and this trend will persist as cities continue to expand. We estimate the impact of this conversion as the amount of land needed elsewhere to give the same yield potential as determined by differences in climate and soil properties. Robust spatial upscaling techniques, well-validated crop simulation models, and soil, climate, and cropping system databases are employed with a focus on populous countries with high rates of land conversion. We find that converted cropland is 30–40% more productive than new cropland, which means that projection of food production potential must account for expected cropland loss to urbanization. Policies that protect existing farmland from urbanization would help relieve pressure on expansion of agriculture into natural ecosystems.

The Effect of Soil-Climate Conditions, Farmyard Manure and Mineral Fertilizers on Potato Yield and Soil Chemical Parameters

If available to farmers, potatoes represent a crop classically fertilized with farmyard manure in the Czech Republic. At the same time, potatoes are a crop sensitive to soil–climate conditions. We evaluated the effect of cattle manure (FYM), manure and mineral nitrogen (FYM + N1, FYM + N2), manure and mineral fertilizers (FYM + N1PK, FYM + N2PK, FYM + N3PK) application and the effect of three soil-climatic conditions (Caslav—maize production area with degraded Chernozem, Ivanovice—maize production area with Chernozem, Lukavec—potatoes production area with Cambisol) over four years (2016–2019) on potatoes yield and soil chemical properties. Of all the factors, yields were most affected by location. Lukavec provided the highest average yields (37.2 t ha−1), followed by Ivanovice (23.5 t ha−1) and Caslav (15.5 t ha−1). The second most important factor was the climatic conditions of the year. Fertilization was the third most important parameter. FYM significantly increased yields compared to Control, but applied alone cannot cover the needs of potatoes. Similarly, the application of FYM and N increases yields, but for the highest yields, it is best to apply FYM + NPK (80 kg ha−1 N). Co-application of FYM and mineral N fertilizers mitigates the negative impact of mineral N on soil pH.

Dynamics of changes in thawing and freezing depth in soils of Western Transbaikalia in different types of permafrost distribution

This study reveals temperature regimes of the three contrasting ecosystems in the permafrost area of Western Transbaikalia: meadow-forest ecosystem, forest-steppe and dry-steppe. Annual profile temperature data show the functioning of the studied soils in cryogenic and long-term-seasonally-freezing temperature regime. The most explanatory temperature variables are temperature penetration above 5°C at 100 cm depth and the amount of days with temperature above 0.5°C and 10°C at 20 cm, 50 cm, and 100 cm depths. Also, this work presents a comparative analysis of indicators of soil climate change and shows the spatial-temporal distribution of the reaction of the thawing and freezing depth in soils.

Soil and Climate Characterization to Define Environments for Summer Crops in Senegal

Investigating soil and climate variability is critical to defining environments for field crops, understanding yield-limiting factors, and contributing to the sustainability and resilience of agro-ecosystems. Following this rationale, the aim of this study was to develop a soil–climate characterization to describe environmental constraints in the Senegal summer-crops region. For the soil database, 825 soil samples were collected characterizing pH, electrical conductivity (EC), phosphorus (P), potassium (K), cation exchange capacity (CEC), and total carbon (C) and nitrogen (N). For the climate, monthly temperature, precipitation, and evapotranspiration layers were retrieved from WorldClim 2.1, CHIRPS and TERRACLIMATE. The same analysis was applied individually to both databases. Briefly, a principal component analysis (PCA) was executed to summarize the spatial variability. The outcomes from the PCA were subjected to a spatial fuzzy c-means algorithm, delineating five soil and three climate homogeneous areas, accounting for 73% of the soil and 88% of the climate variation. To our knowledge, no previous studies were done with large soil databases since availability field data is often limited. The use of soil and climate data allowed the characterization of different areas and their main drivers. The use of this classification will assist in developing strategic planning for future land use and capability classifications.

Downregulation of the microbial protein biosynthesis machinery in response to weeks, years, and decades of soil warming

How soil microorganisms respond to global warming is key to infer future soil-climate feedbacks, yet poorly understood. Here we applied metatranscriptomics to investigate microbial physiological responses to medium- (8 years) and long-term (>50 years) subarctic grassland soil warming of +6 °C. Besides indications for a community-wide upregulation of central metabolisms and cell replication we observed a downregulation of the protein biosynthesis machinery in the warmed soils, coinciding with a lower microbial biomass, RNA, and soil substrate content. We conclude that permanently accelerated reaction rates at higher temperatures and reduced substrate concentrations results in a cellular reduction of ribosomes, the macromolecular complexes carrying out protein biosynthesis. Later efforts to test this, including a short-term warming experiment (6 weeks, +6 °C), further supported our conclusion. Downsizing the protein biosynthesis machinery facilitates liberation of energy and matter, allowing microorganisms to maintain high metabolic activities and cell division rates even after decades of warming.