Net Requirements Research Articles

The impact of the biodiversity net gain requirement on the cost management of projects

This briefing is a legal overview of the potential impact of the biodiversity net gain (BNG) requirement introduced by the United Kingdom government’s Environment Act 2021 on the cost management of a major or minor development project. This BNG requirement aims to protect the environment from the negative impacts of construction processes and activities. It relates to the United Kingdom government’s overarching goal to embed a broad ‘environmental net gain’ principle in the planning system, as per the United Kingdom government’s refreshed 25-year Plan of February 2023. The paper provides an overview of when BNG is required, how to provide it, its duration, the metrics require for assessments, and the exemptions for providing such as requirement as well as the BNG plan approval process. It refers to government guidance and to recent developments since the inception of the new United Kingdom government in July 2024. The overall result of implementing this new requirement is that there are added costs to factor into the planning of a project, more scrutiny from relevant planning authorities, and potentially more uncertainty about the cost management of relevant projects, due to many factors.

Remote sensing-based green and blue agricultural water footprint estimation at the river basin scale

Since the development of Water Footprint environmental indicator, significant research on blue and green crop water use and the respective water footprint estimations has been published. Such research is commonly approached using different methodologies that leverage tabulated values for crop development characterisation, while studies based on remote sensing data are less abundant, despite crop monitoring using remote sensing-based vegetation indices having demonstrated great capabilities and operability. To help fill this gap, we present a methodology that uses a remote sensing vegetation index time series from Sentinel-2 satellite near infra-red and red spectral bands data to derive basal crop coefficient time series to subsequently be used under the Remote Sensing-based Soil Water Balance approach that follows the globally operative FAO56 procedure. It provides pixel-based temporal and spatially distributed estimations of net irrigation requirements and adjusted crop evapotranspiration, with the aim being to divide up the latter and estimate the remote sensing-based green and blue crop water use and the subsequent green and blue water footprint. This is all done under the Agricultural Water Footprint Assessment framework for a growing crop or tree. This methodology was applied over a large, crop-diverse Spanish river basin district (Júcar) and across two different climatological years (humid vs. dry). Its feasibility was demonstrated by the acceptable behaviour of the remote sensing-based blue crop water use estimation for different herbaceous and woody crops, against the official dataset for irrigation water accounting at two water management scales (of a relative mean absolute error of 15.4 % in the case of the largest water user association and of 17.1 % in the case of the river basin water authorities’ own estimations). The proposed approach, which we call Remote Sensing-based Agricultural Water Accounting and Footprint, aims to provide reliable and accurate spatially and temporally distributed thematic cartography about the remote sensing-based blue and green crop water use and water footprint. This information is essential for water managers with the goal of generating transparent and complementary information to incorporate into their own working scales.

28 Integrating homeostasis in practical mineral supplementation recommendations

Abstract A long-established objective in ruminant nutrition is an accurate supply of the 4 main trace metal nutrients Zn, Cu, Mn, and Fe, respecting bioavailability, nutritional interactions, and nutrient tolerance. Although, current dietary supplementation practices, justified by the multiple uncertainties of trace metal supply, results in dietary levels that widely exceed nutritional guidelines. Additionally, reference feeding recommendations are defined assuming fixed and highly conservative uptake coefficients, an approach that disregards the opportunity, and limitations, of absorptive regulation, the main homeostatic mechanism of these nutrients. Mitigating deficiency risks by generous supplementation can result in a generally overlooked risk, exceeding tolerable trace metal availability. Complete nutrient balance studies have recently described the overwhelming homeostatic downregulation of trace metals at dietary levels that are not uncommon in practice. This finding calls for a novel approach to define supplementation that resolves this conundrum of trace metal adequacy. This approach integrated 3 elements: a stochastic analysis of native dietary supply; a stochastic analysis of net nutrient requirements; and the identification of the upper and lower boundaries of homeostatic regulation for these 4 nutrients in the bovine species. This last, aims to resolve the main limitation of current dietary guidelines, using the potential maximum uptake rates in homeostatic upregulation, and the minimum uptake rates achievable by downregulation, instead of assuming fixed uptake rates. As result, this approach delivers dietary supply ranges of adequate supply, instead of a minimum dietary level to meet dietary adequacy. The probability distribution of nutrient supply was determined by dry-matter intake variability, diversity in dietary composition, and variability of nutrient occurrence in feedstuffs. The probability distribution of net nutrient requirements was defined by the variability of the components of a classic factorial requirement approach applied to different animal conditions. A maximum apparent absorption efficiency was determined to define lower supply boundaries using published datasets. Upper boundaries were defined as the dietary supply level beyond which apparent absorption empirically has shown to exceed net requirements. As expected, this risk-based approach resulted in much lower supplementation recommendations than current reference models. However, it supports the value of preventive supplementation of Zn and Cu to growing and lactating animals, and Cu to non-lactating non-growing cows. This assessment also indicates merit in Mn supplementation to growing bovines. Furthermore, it confirms that under all circumstances native dietary Fe meets nutritional needs, but it also illustrates a tolerance risk to native Fe supply under multiple productive scenarios. Most interestingly, this analysis illustrates the risk of exceeding trace metal tolerance boundaries with common levels of supplementation under common conditions. This approach offers a novel perspective to trace metal supplementation, pointing at an opportunity to improve nutritional adequacy by reconsidering supplementation practices.

Assessment of Water Resources Potential of Ogun River for Irrigation Purposes at Middle Ogun Irrigation Project

The Middle Ogun Irrigation Project (MOIP) was conceived by the Federal Government of Nigeria to boost agricultural food production in the southwestern part of the country using modern irrigation facilities. However, water supply from the Ikere Gorge dam has been intermittent, particularly at the intake weir of this project, despite the enormous water resources on the dam. Therefore, this project assessed the water resources potential at the Odo Ogun intake weir guage station of the Middle Ogun Irrigation Project and evaluated the seasonal irrigation requirements on irrigation fields. The Flow Duration Curve (FDC) was derived at the gauge site for streamflow discharge from four quartiles and percentage reliability of Q95%, Q75%, Q50% and Q25%, which gave 32.40, 55.01, 60.00 and 90.00 m3/s, respectively. Hydrological modelling of the catchment was carried out using the MapWindow Soil and Water Assessment Tool (MWSWAT) for ten delineated sub-basins on the catchment and the average annual yield from the catchment was 10,094.00 mm/year. The net seasonal irrigation requirement of crops grown was evaluated using CROPWAT 8.0 and gave 428.46 mm per planting season.

Integrating hydrologic modeling and satellite remote sensing to assess the performance of sprinkler irrigation

ABSTRACT Improving irrigation water management is a key concern for the agricultural sector, and it requires extensive and comprehensive tools that provide a complete knowledge of crop water use and requirements. This study presents a novel methodology to explicitly estimate daily gross and net crop water requirements, actual crop water use, and irrigation efficiency of center pivot irrigation systems, by mainly utilizing the Sentinel-2 MultiSpectral Instrument (MSI) imagery at the farm scale. ETMonitor model is adapted to estimate actual water use (as the sum of canopy transpiration and evaporation of water intercepted by canopy and evaporation from soil) at daily/10-m resolution, benefiting from the high-resolution Sentinel-2 data and thus to assess the irrigation efficiency at the farm scale. The gross irrigation water requirement is estimated from the net crop water requirement and the water loss, including the water droplet evaporation directly into the air during application before droplets fall on the canopy and canopy interception loss. The method was applied to a pilot farmland with two major crops (wheat and potato) in the Inner Mongolia Autonomous Region of China, where modern equipment and appropriate irrigation methods are deployed for efficient water use. The estimated actual crop water use showed good agreement with the ground observations, e.g. the determination coefficients range from 0.67 to 0.81 and root mean square errors range from 0.56 mm/day to 1.24 mm/day for wheat and potato when comparing the estimated evapotranspiration with the measurement by the eddy covariance system. It also showed that the losses of total irrigated volume were 25.4% for wheat and 23.7% for potato, respectively, and found that the water allocation was insufficient to meet the water requirement in this irrigated area. This suggests that the amount of water applied was insufficient to meet the crop water requirement and the inherent water losses in the center pivot irrigation system, which imply the necessity to improve the irrigation practice to use the water more efficiently.

Agricultural Water Management for Rice Production: A Comprehensive Analysis

The identified problem revolves around establishing the water requirements for rice seeding, growth, and maturity in hot climatic conditions. This study reviews the net water requirement for rice growth or production under various climatic conditions in the Cross River Basin. It was observed that the water requirement from seeding to harvest varies from location to location, maintaining a FAO range, as postulated by Brouwer et al., 1986, ultimately falling between 450mm to 700mm for hot weather.The methodology used for investigating the Net Irrigation Water Requirements for rice growth to maturity involves the application of New_Clim Location and CropWater software. These tools were utilized to compute Reference Evapotranspiration (ETo) and Crop Water Requirements (CWR) for the net irrigation water requirements of rice, respectively. The data were obtained from meteorological stations within the Cross River Basin. In rainfed conditions, no water stress is practically observed throughout the entire crop cycle, affirming that no irrigation system is needed in such a specific climate. This study uses data generated through New_LocClim as input into CropWat, which, among other factors, determines the net water requirement for rice growth and production. Consequently, the results obtained from the use of the CropWat model in determining rice water requirements for Obudu, Nkari, Ikom, and Ijegu-Yala were 633.7 mm, 397.9 mm, 303.0 mm, and 548.4 mm, respectively. The water requirement of only two locations, Obudu and Ijegu-Yala, fell within the FAO-suggested range of 450 mm to 700 mm (Brouwer et al., 1986) for hot climates, while Nkari and Ikom LGAs did not comply with Brower et al., 1986 postulation due to their location in a relatively less hot climate.

Irrigation Water Management in a Water-Scarce Environment in the Context of Climate Change

Climate change has a considerable impact on irrigated agriculture, which is vital for food and fiber production. In this study, in the context of climate change, simulation model CROPWAT 8 was employed to compute the reference evapotranspiration, and net irrigation water requirement for wheat, barley, maize, sugar beet, potato, tomato, and date palm. In addition, the WaterGEMS model was utilized to design a new sprinkler irrigation system to run long-term simulations of hydraulic behavior within pressurized pipe networks to irrigate 43 acres for two arid sites (Siwa Oasis and West Elminya fields) inside the 1.5-million-acre groundwater irrigation project in the Egyptian western desert. Five scenarios for climate change were employed in the current (1991–2023), representative concentration path (RCP) 8.5 greenhouse gas emission scenarios for the 2040s, 2060s, 2080s, and 2100s. Mean ETo values for the current scenario show 4.56 and 5.7 mm for the Siwa Oasis and West Elminya fields, respectively. The climate changes cause an increase of the reference evapotranspiration by 4.6, 5.9, 9.4, and 12.7% for RCP: 8.5 greenhouse gas emissions for the 2040s, 2060s, 2080s, and 2100s scenarios, respectively, for the Siwa Oasis field. On the other hand, an increased ratio for the reference evapotranspiration by 4.2, 5.4, 8.6, and 11.6% was observed for the scenarios in the West Elminya field, respectively. The designed sprinkler system indicated a capacity of 111.4 m3 h−1 and 167 m3 h−1 for Siwa and West Elminya fields, respectively. The study suggests using crop patterns for wheat, barley, potato, and sugar beet to save irrigation water.Graphical abstract

An Analytical Study on the Measurement of Agricultural Net Irrigation Water Requirements

The net irrigation water requirement (NIWR) in the irrigated area is the “terminal” of water-use efficiency and the basis for implementing quota management and water-saving incentives. Also, it is significant for farmland water management and water conservation in irrigated areas. In light of the average water consumption per mu and the crop area, which are two key indicators of the NIWR, this paper adopts the field selection measurement method and the statistical method based on the image patches achieved by China’s third national land survey to acquire the data of water consumptions and crop areas. In this case, four principles of field selection are proposed, including “basic requirements”, “moderate size”, “controllable water inflow”, and “measurement practicality”, in an attempt to increase the number of fields selected for analysis. In addition, based on the image patches, the “complete investigation” and the “typical investigation” are suggested for irrigated areas at different scales to determine the crop areas, which are proven practicable and available for evaluating the water-use efficiency of irrigated areas at different scales.

A new system of phosphorus and calcium requirements for lactating dairy cows.

Accurately predicting phosphorous (P) and calcium (Ca) dietary requirements is critical for optimizing dairy cattle performance, and minimizing mineral excretions and ecosystems eutrophication. This study provides a new factorial system to determine net and dietary P and Ca requirements for maintenance and lactation, derived from a meta-regression of mineral trials involving lactating dairy cows. A comprehensive global database was constructed from 57 peer-reviewed articles of mineral balance trials, with a wide range of dietary and animal performance data. We estimated the net requirements for maintenance from the intercept of a nonlinear equation between mineral intake and the sum of total fecal and urinary excretions, which is an estimate of endogenous mineral loss. Mineral secreted in milk was used to obtain net requirements for lactation. The mineral metabolizable coefficient was quantified through observed (treatment means) mineral intake and total fecal and urinary excretions, discounting the estimated endogenous excretions from our proposed models. The nonlinear models of total fecal and urinary mineral excretion were evaluated (observed versus predicted values) using a 5-fold cross validation approach. The models to estimate the sum of endogenous fecal and urinary excretions of P (0.135±0.043 g P/kg BW0.75) and Ca (0.360±0.144 g Ca/kg BW0.75) exhibited suitable precision and accuracy; r = 0.89 and 0.79, concordance correlation coefficient = 0.85 and 0.77, and root mean square prediction error = 24.1 and 20.5% observed means, respectively. Dietary variables (forage level, fiber, starch, crude protein, and ether extract) did not affect the metabolizable coefficient (MC) of P and Ca; therefore, an overall dietary MC of P (0.69±0.01) and Ca (0.65±0.02) were proposed. Our new system estimates lower net and dietary P requirements for lactating dairy cows compared to the NASEM-2021 and NRC-2001 models, but slightly higher Ca requirements than NASEM-2021.This proposed system holds potential to reduce the use of phosphorus in diets for dairy cows, and thus to enhance economic efficiency and environmental sustainability of the dairy industry.

Unveiling the Thirst: Revealing the Water Requirements of Gujrat's Thriving Crops using CROPWAT 8.0

Water plays an essential role in agriculture, serving as a primary reserve that directly impacts crop production and food security. Water conservation is critical for sustainable agriculture and the well-being of communities and ecosystems, chiefly due to the increasing global demand and rising water dearth concerns. The water needs of crops and irrigation scheduling in the district Gujrat, Pakistan, are currently missing enough information. Therefore, this study was conducted to determine the crop water requirements and establish irrigation schedules for the major crops in district Gujrat, Pakistan. The crop water requirement (CWR) and irrigation schedules were determined by CROPWAT 8.0 by using the input climate data obtained from the POWER-NASA website from 1991-2020. Other than climatic data, crops (wheat, rice, sugarcane, and maize) and soil information were added from CROPWAT 8.0 pre-existing data. The crop planting dates were estimated by Ayub Agriculture Research Institute (AARI). The gross and net crop water requirements are 624.3 mm and 491.3 mm for wheat, 1805.2 mm and 1768.3 mm for rice, 4135.1 mm and 3537.2 mm for sugarcane, and 1203.5 mm and 1051.4 mm for maize. The deployment of CROPWAT 8.0 proves to be valuable in precisely assessing crop water requirements and computing irrigation scheduling. The study's outcomes show the potential to boost food production and aid in well-organized water reserve management.

Modelling the response of tomato on deficit irrigation under greenhouse conditions

To optimize crops irrigation strategy is crucial to improve the production sustainability in a climate change scenario characterized by an ever-increasing water shortage. Crops simulation models, combined with experimental data, can be useful tools. AquaCrop, a crop water productivity model, has been widely used to reach this aim in open field condition but it has been limited adopted under greenhouse conditions. This study aims to calibrate and validate AquaCrop model through a greenhouse tomato cultivation using a split plot experimental design. Crop irrigation management was the main treatment [full irrigation (FI) at 100 % crop evapotranspiration (ETc) vs. deficit irrigation (DI) at 75 % of FI] and fertilization [no fertilization, mineral fertilization, organic fertilization with compost, and organic fertilization with sieved (< 2 mm) compost] the subplots. Fresh yield, above-ground biomass, water productivity, and net irrigation requirements were simulated. The validated model also permitted to evaluate the impacts of changing temperature outside the greenhouse on fruits yield, biomass, and water productivity using 30 years of historical weather data. The results showed that the model accurately estimated crop parameters, although it tended to overestimate soil water content. On average, DI reduced fruit yield by 14.1 % compared to FI. Over the last 30 years, the validated model permitted to calculate an average fruits yield reduction due to DI of 12.6 %. Our findings suggest that models like AquaCrop can assist in optimizing greenhouse agriculture by predicting crop performance under different conditions. Our study also highlights that external temperature and AquaCrop can be used to estimate tomato yields in the greenhouse by providing decision support tools for end-users (farmers, farmer associations, and policymakers) seeking sustainable and efficient greenhouse farming practices in a changing climate.

Comparing water requirements of urban landscape plants in an arid environment: An application of the WUCOLS method in the National Botanical Garden of Iran

Water scarcity is a pressing issue in many arid and semi-arid regions worldwide, requiring effective water resource management. To address this challenge in the National Botanical Garden of Iran, we analyzed the water requirements for the irrigation of ten tree species over the entire growth period, spanning from January 2021 to January 2022. We employed the Water Use Classification of Landscape Plants (WUCOLS) method, and used remote and on-site measurements to obtain the required data (i.e., enhanced vegetation index, leaf area index, rainfall, and site and species characteristics) for the analysis. We found that Ficus carica L., Cercis siliquastrum L., and Ulmus glabra Hudson had high landscape evapotranspiration (ETL) values, showing their elevated water requirements. Among all the species studied, F. carica, C. siliquastrum, and U. glabra showed the highest total ETL, reaching 1033, 1031, and 1002 mm respectively, highlighting their overall greater water needs throughout the study period. Further, we computed the annual net water requirement (IRn) for each plant species, taking into account the effective rainfall of 123.5 mm during the growth period of the study garden. We found that F. carica, C. siliquastrum, and U. glabra had the highest IRn among all the species with values of 950, 948, and 919 mm respectively. In contrast, Olea europaea L., and Quercus robur L. had the lowest IRn values of 681, and 711 mm, respectively. Additionally, we assessed the difference between annual irrigation values (AI) and gross water requirement values (IRg). Cercis siliquastrum and F. carica with values of −519 mm and − 511 mm had the largest negative differences, indicating that these species received the least irrigation water in comparison with their gross water requirements among all the species. In contrast, Cotinus coggygria, and O. europaea, with values of 182 mm and 125 mm had the largest positive differences, suggesting that these species received the most irrigation water in comparison with their gross water requirements among all the species. Our findings hold significance for the management of urban green spaces, including botanical gardens, parks, and street trees, contributing to the well-being of urban residents and visitors.

Sustainable Water Resources Management under Climate Change: A Case Study with Potato Irrigation in an Insular Mediterranean Environment

Potato cultivation is a significant agricultural activity worldwide. As a staple food in many countries, potatoes provide essential nutrients and are a significant source of income for farmers. This paper investigates current and future net irrigation requirements for potatoes in combination with LCA (life cycle assessment) to assess the GHG emissions due to irrigation. Potato cultivation in Cyprus is used as a model for insular environments, which are often neglected from such studies. The models suggest that an increase in net irrigation requirements is expected but there is a large variability among locations and between years. The increase in rainfall that some of the models predict does not mean that this water will be effectively stored in the soil (and reduce irrigation requirements). The GHG emissions due to potato irrigation in Cyprus are estimated to be 1369.41 tons CO2eq and expected to decrease after 2030 by 35%, mainly due to changes in the electricity mix (from heavy fuel to renewable energy). Further research including other important (irrigated) crops in the island will support the development of strategies towards sustainable resources management under climate change.

Simulation of Irrigation Strategy Based on Stochastic Rainfall and Evapotranspiration

The North China Plain plays a pivotal role in China’s crop production, contributing to 30% of the maize yield. Nevertheless, summer maize in this region faces challenges due to climatic constraints characterized by concurrent high temperatures and rainfall during the growing season, resulting in a relatively high evapotranspiration rate. In this study, we explored eight soil moisture-based threshold irrigation strategies, consisting of two upper limits and four lower limits, along with a rainfed mode (E). The upper and lower irrigation limits are expressed as a percentage of the field’s water-holding capacity (sfc). For the four full irrigation modes (A1, A2, A3, A4), the lower limits were set at 0.6 sfc, 0.6 sfc, 0.5 sfc, and 0.5 sfc, respectively. The upper limits were defined at two levels: 0.8 sfc for A1 and A2 and sfc for A3 and A4. Similarly, for the four deficit irrigation modes (B1, B2, B3, B4), the lower limits were established at 0.4 sfc, 0.4 sfc, 0.3 sfc, and 0.3 sfc, respectively, with the upper limits set at two levels: 0.8 sfc for B1 and B2 and the full sfc for B3 and B4. To investigate the impact of rainfall and potential evapotranspiration on these irrigation modes under long-term fluctuations, we employed a stochastic framework that probabilistically linked rainfall events and irrigation applications. The Monte Carlo method was employed to simulate a long-term series (4000a) of rainfall parameters and evapotranspiration using 62 years of meteorological data from the Xinxiang region, situated in the southern part of the North China Plain. Results showed that the relative yield and net irrigation water requirement of summer maize decreased with decreasing irrigation lower limits. Additionally, the interannual variation of rainfall parameters and evapotranspiration during the growing season were remarkable, which led to the lowest relative yield of the rainfed mode (E) aligned with a larger interannual difference. According to the simulation results, mode A4 (irrigation lower limit equals 0.5 sfc, irrigation upper limit equals 0.8 sfc) could be adopted for adequate water resources. Conversely, mode B2 is more suitable for a lack of water resources.

CROP WATER REQUIREMENT IN A SUB-WATERSHED OF MAHABUBNAGAR DISTRICT OF TELANGANA FOR KHARIF RICE CULTIVATION USING GEOSPATIAL TECHNIQUES

In a sub-watershed of the Mahabubnagar district of Telangana state, India, the paper focuses on estimating the irrigation water requirements of paddy crops for the kharif season from 2019 to 2021. The Random Forest Classifier in Google Earth Engine has used Sentinel-2 to determine the area that is being used for paddy cultivation. Using the Hargreaves model, potential evapotranspiration (ETο) has been calculated. The crop coefficient (Kc) for paddy and potential evapotranspiration (ETο) were used to calculate the crop's water requirements (Etc). Utilizing gridded rainfall data from the CHRS (Center for Hydrometeorology and Remote Sensing) - PERSIANN-Cloud Classification System (PERSIANN-CCS 4km x 4km), effective rainfall was calculated. To calculate the amount of irrigation water needed, effective rainfall and crop water needs were taken into consideration. Net irrigation water need was calculated by assuming 30% losses. The amount of water needed for paddy is calculated by multiplying the paddy cropped area by the net irrigation water requirement.

Assessment of Net Irrigation Requirements for Spring Wheat and Spring Maize in Shiyanghe Watershed, Northwestern China

Assessment of Net Irrigation Requirements for Spring Wheat and Spring Maize in Shiyanghe Watershed, Northwestern China

The challenge of rehabilitating relocated listed heritage Buildings: Requirements and opportunities

This study evaluates three listed farmhouses in Ørland Municipality which are going to be relocated and rehabilitated according to current Norwegian standards and requirements. Accordingly, the study assesses possible challenges and solutions regarding energy upgrading and restoration while preserving their historic features and cultural heritage. The study suggests solutions for the energy rehabilitation of the three farmhouses based on a literature review, hygrothermal simulations and energy simulations. These solutions include thermal post-insulation of external walls and above the framework of joists against the cold attics with mineral wool, vacuum insulation panels (VIP), and aerogel blankets. Additionally, fenestration renovation options and the potential for implementation of building integrated photovoltaics (BIPV) are reviewed. Lastly, simulations of multiple energy-saving measures for each of the farmhouses have been conducted.A new foundation due to the relocation, together with post-insulation of the cold attic are found to be feasible measures considering the preservation of architectural appearance and authenticity. Regarding the external walls, post-insulating externally is preferable for the farmhouses considering moisture issues and interior space savings. However, it is important to consider any possible loss of cultural heritage value. Alternatively, internal thermal insulation with aerogel blankets may be a feasible solution due to its high thermal resistance applying small thicknesses. The results show that in some cases, enhancing old original windows with a secondary glazing is an equally good solution compared to a total replacement of the windows, and is recommended for cultural preservation. Implementation of BIPV contributed to meet the net energy demand requirement. Nevertheless, it is recommended that the chosen BIPV systems resemble an accepted roofing material from the regulatory requirements, e.g., slates, to accommodate the building’s architectural aesthetics and authenticity.This study provides insight and recommendations for the rehabilitation of three listed traditional farmhouses in Trøndelag County, addressing energy efficiency while preserving their cultural significance. The findings show that it is possible to achieve today’s energy requirements when rehabilitating listed heritage buildings. Results from energy simulations show that a reduction in net energy demand between 55 % and 75% is possible, while it is essential to note that each building is unique, and a case-by-case approach is needed. Nevertheless, the findings can be applicable for a general energy upgrading of heritage buildings.

Energy and protein requirements for maintenance and weight gain of Canindé goats supplemented on pasture in the semi-arid region

The purpose of this study was to estimate the carcass composition, and energy and protein requirements for maintenance and weight gain of Canindé goats supplemented on pasture in a semi-arid region. Forty-six castrated animals, with initial body weight (BW) of 15.7 ± 0.96 kg, grazing in Caatinga were used. Six animals were slaughtered at the beginning of the experiment representing the initial carcass composition (reference animals; 16.1 ± 1.15 kg BW), while the other animals were randomly distributed in four treatments (concentrate supplementation at 0%, 0.5%, 1.0%, and 1.5% BW), with ten animals per treatment. When one of the animals of each group reached 25 kg BW, all animals in that group were slaughtered. The whole empty body was weighed, ground, homogenized, and sampled for further chemical analyses. The level of supplementation influenced dry matter intake, retained energy, and body weight gain of Canindé goats. The energy (kcal/kg) and fat (g/kg EBW) contents in the carcass of goats of 15, 20, and 25 kg were 2.29 and 86.11, 2.39 and 113.48, and 2.47 and 140.53, respectively. The minimum nitrogen losses were 188 mg N/EBW0.75. The net and metabolizable energy for maintenance were 72.11 kcal/EBW0.75/day and 2.19 g/kg EBW0.75/day, respectively. The net and metabolizable protein requirements were 2.19 and 1.88 g/kg EBW0.75, respectively. The net energy and protein requirements for weight gain ranged from 2.61 to 2.81 Mcal/kg EBW gain and 194.37–222.55 g protein/kg EBW, respectively, for animals from 15 to 25 kg BW. It is concluded that the energy and protein nutritional requirements of Canindé goats supplemented on pasture in the semi-arid region vary according to body weight.

Protein requirements for pregnant dairy cows

We aimed to estimate the protein requirements of pregnant Holstein × Gyr cows. Sixty-one Holstein × Gyr (HG) cows were used, with an average initial BW of 480 ± 10.1 kg and 5 ± 0.5 yrs of age. Cows were divided into 3 groups: pregnant (n = 43), non-pregnant (n = 12), and baseline (n = 6). Baseline animals were slaughtered before starting the experiment to estimate the initial body composition of the remaining animals. Pregnant and non-pregnant cows received 2 diets: maintenance and ad libitum. Pregnant cows were slaughtered at 139, 199, 241, and 268 gestation days (GD). First, we used data only from non-pregnant cows to determine the requirements for maintenance and growth in adult cows. The requirements of metabolizable protein for maintenance (MPm; g/EBW0.75/d) were estimated using a linear regression between the metabolizable protein intake (MPI, g/d) and average daily gain (g/d), and the MPm was defined as the intercept divided by the average BW0.75. Net protein requirements for gain (NPg; g/d) were estimated by the first derivative of the allometric equation between final crude protein (CP) in the body (kg) and the final EBW (kg). The efficiency of use of metabolizable protein for gain (k) was calculated from the regression between the retained protein (g/EBW0.75/d) and the MPI (g/EBW0.75/d), and k was the slope of this regression. The MPI was estimated by combining microbial protein synthesis (purine derivatives) with the digestible rumen undegradable protein [(total protein intake minus RDP) × intestinal digestibility]. Second, an exponential model was used to fit the protein accumulation in the gestational components in the function of GD. The first derivative of that model was considered the net requirement for gestation (NPgest). The efficiency of protein utilization for gestation (kgest) was calculated by the iterative method using the equation: Δ = MPI - (MPm + NPg/kg + NPgest/kgest). The iteration was performed aiming at a zero deviation between observed MPI and MP estimated by the requirements determined herein. We obtained a value of 3.88 g/EBW0.75/d for MPm. The estimation of NPg can be calculated according to the following equation: NPg = 0.716 × (EBWopen-0.308) × EBGcorrected, where EBWopen is the empty BW (kg) for non-pregnant animals and EBGcorrected is the empty body gain (kg/d) corrected for the gestational component. The k was determined as 0.347. The net protein requirements for gestation (NPgest) were determined as NPgest (g/d) = 0.0008722 × exp(0.01784 ×GD) × (calfweight/35). The efficiency of using metabolizable protein for gestation (kgest) was 0.625. It is important to highlight that different methods of MP estimates should not be mixed and that the proposed method requires the estimate of microbial protein (estimate it via urinary estimates) and might be a limitation for practical application. In conclusion, new studies should be conducted to validate our results and the methodology adopted to determine protein requirements for pregnancy in dairy cows. Due to the pattern of protein accumulation in the gestational components, we suggest that exponential model to describe protein requirements for pregnancy for dairy cows.

Irrigation development as a booster of the multifunctional roles of paddy rice

AbstractTo promote sustainable production and the multiple roles of paddy rice, it is essential to expand our understanding of the impacts of different management options, with particular emphasis on irrigation development. The impact of various management practices (supplementary irrigation during the rainy season, improved fertilization, cropping during the dry season and mulching practices) on irrigation water requirements, crop productivity and the multifunctional roles of irrigated paddy rice was evaluated in diverse agro‐ecological zones of Zambia, by using the AquaCrop model. Irrigation development has been demonstrated to boost paddy rice production (by 8%) in the southern districts by providing supplementary irrigation (about 150 mm) during the rainy season. Additionally, supplementary irrigation during the rainy season can make improved fertilization more attractive, doubling the yield rise under rainfed conditions. The required irrigation development would also enable paddy rice cropping intensification by allowing for dry season sowing (with net irrigation requirements from 700 to 800 mm). Moreover, the associated straw production increase could also play an important role as mulch during the dry season, reducing the net irrigation requirements by 15%. These findings will enable policymakers to make informed decisions regarding investment strategies and policies.