INTEGRATED CROP-LIVESTOCK SYSTEMS: LESSONS FROM NEW YORK,BRITISH COLUMBIA,AND THE SOUTH-EASTERN UNITED STATES

• Livestock production in North America has moved to fewer farms with greater inventories • Land application of livestock manures is a preferred nutrient recycling strategy • Confined animal feeding operations have challenges to utilize livestock manure sustainably • Integration of livestock and cropping systems is possible on a farm or among farms • Nutrient balance is needed for environmental sustainability Livestock production in the United States (US) and Canada is diverse, but shows a common trend in most livestock sectors toward fewer farms producing the majority of animal products despite a large number of farms still small in production scale. The migration to larger and more concentrated animal feeding operations in beef finishing and poultry, swine, and dairy production allows processors to streamline supplies to meet market demand for abundant, low-cost livestock products, whether that be for packaged meat, dairy products, or eggs. With concentration of livestock operations comes the challenge of managing manures. When sufficient land is available and nutrients are needed, livestock manure is an excellent nutrient source and land application is the preferred method of recycling this resource. However, when livestock production is constrained in a geographical area and animal densities are high, manure may become an environmental liability with potentially greater risk for runoff and leaching of nutrients, emission of odors, ammonia, and greenhouse gases, and release to the environment of pathogens and chemicals of emerging concern. Addressing these challenges now and into the future requires learning from mistakes and adopting successful approaches. We describe different levels of integration between livestock and crop producers in New York, British Columbia, and the south-eastern US as learning opportunities to improve economic and environmental sustainability. Examples show that effective solutions should recognize (1) manure has value and is not just a cost, (2) farmers, farm advisors, extension educators, nutrient management planners, crop advisors, nutritionists, state agency personnel, regulators, and university researchers need to be active participants in development of solutions, and (3) change to a sustainable future requires a combination of government regulation and outcome-based incentives.     

Application of a simulation model for assessing integration of smallholder shifting cultivation and sheep production in Yucatán, Mexico

Simulation models are effective tools to examine interactions between livestock, cropping systems, households, and natural resources. Our study objective was to use an integrated livestock and crop model to assess the outcomes from selected suites of management decisions observed in smallholder sheep-cropping systems of Yucatán, Mexico. The scenarios contrasted specialized systems versus mixed farming, and evaluated the outcomes of increased crop-livestock integration. Mixed enterprise scenarios involving sheep provided more income than specialized enterprises, and capitalized on a lower price of on-farm maize grain, efficient utilization of surplus labor, and availability of common land. Labor and management income was greatest for the unintegrated and partially integrated crop and livestock scenarios. It was more profitable for producers to sell excess grain and maize stover, and use common land to feed the livestock, suggesting that increased integration does not always result in improved outcomes. The results are consistent with a system not yet pushed to the point where integration is inevitable. For all sets of scenarios, the model structure was able to accommodate subtle management differences to produce appropriate biophysical, labor, and economic outcomes. We conclude there is potential to use similar model development methods to describe other crop-livestock systems, thus providing tools for learning, scenario analysis, and impact assessment.     

Effect of Soil Phosphorus Levels on Phosphorus Runoff Concentrations from Turfgrass

Phosphorus (P) loss from urban areas has been identified as a major contributor to declining surface water quality. The objective of this study was to determine the relationship between extractable soil P, depth of soil sampling, and dissolved reactive P (DP) concentration in runoff from turfgrass areas. At each site, runoff was generated on turfgrass and adjoining areas where turfgrass cover was removed. Across all six locations and the wide range of nutrient management schemes, variation of extractable soil P concentration and saturation ratios of 0–2cm samples accounted for 49–59% (r ² = 0.49–0.59, n = 92) of variation of DP concentration in runoff from bare soil and soil with turfgrass cover. Despite a high degree of soil P stratification, changing sampling depth generally did not improve the relationship between soil test P and runoff DP concentrations. Across the narrower range of soil P levels common to lawns in New York (0–50mg kg^?1 Morgan extractable soil P), none of the soil tests or P saturation levels (for 0–2cm depth) could accurately predict runoff P concentrations from soil with turfgrass cover (r ² = 0.02 to 0.23, n = 72). For bare soil plots, restricting the analysis to the same range (<50mg kg^?1 Morgan extractable P) did not alter the relationship between soil test P and runoff DP concentrations observed for the entire range (0–658mg kg^?1) of soil-test P concentrations. These results suggest soil testing will not be an effective tool to predict runoff from turfgrass areas across the range of soil P levels common to New York State.     

Phosphorus Management of Lucerne Grown on Calcareous Soil in Turkey

ABSTRACT

Lucerne or alfalfa (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires phosphorus (P) additions as the soils are naturally P deficient. Phosphorus sorption isotherms were used to estimate P fertilizer needs for lucerne grown for two years in a 3-cut system on a calcareous P deficient Aridisol in eastern Anatolia, Erzurum province, Turkey. Annual P applications ranged from 0–1200 kg P ha^?1. The Langmuir two-surface adsorption equation was used to derive the maximum P sorption capacity of unamended soil and to determine soil solution P, maximum buffer capacity (MBC), equilibrium buffer capacity (EBC), and P saturation at the optimum economic P rate (OEPR) for dry matter (DM) production. Soils were tested for Olson P at the onset of the study and after two years of P applications. In both years, tissue was analyzed for P content at flowering prior to first cutting. The OEPR (2-year average) was 754 kg P ha^?1 yr^?1 corresponding with a soil solution P concentration of 0.30 mg L^?1, a DM yield of 8725 kg DM ha^?1, and $528 ha^?1 annual profit. The P content of leaves at flowering increased linearly with P application beyond 100 kg P ha^?1 and was 3.2 g kg^?1 P at the OEPR. The unfertilized soil had an EBC, MBC, P saturation, and X_max of 3304 mL g^?1, 3401 mL g^?1, 6%, and 1086 mL g^?1, respectively, whereas two years of fertilization to the OEPR decreased EBC and MBC to 358 mL g^?1 and 540 mL g^?1, and increased P saturation and Olsen P to 56% and 32 mg kg^?1, respectively. These results suggest a P saturation >50% or Olsen P >30 mg kg^?1 are needed to maintain an optimum soil solution concentration of 0.30 mg L^?1 in this calcareous Aridisol. Similar studies with different soils and initial soil test P levels are needed to conclude if these critical soil test values can be applied across the region.     

Nitrogen response models for winter cereals grown for forage

Forage double cropping can increase production, reduce erosion risk and improve soil health. Farmer experience in the north‐eastern USA shows that winter cereals can, in 3–4 weeks (Feekes 9 harvest), produce high quality forage given sufficient N at dormancy break. Here, we evaluate crop response models to determine the most economic rate of N (MERN) for forage winter cereals. Sixty‐three on‐farm N‐rate trials (0, 34, 67, 101, 135 kg N/ha) were conducted in New York from 2013 to 2016. Trials were divided into four categories: (a) no yield response to N (group 1; 20 trials); (b) yield plateau exceeded the highest N rate (group 2; one trial); (c) the MERN was below the lowest N rate (group 3; seven trials) and (d) all other N‐responsive trials (group 4; 35 trials). For group 4, three statistical models were compared (quadratic plateau, exponential and square root plateau). Statistical, environmental and economic criteria showed that the quadratic plateau fits the data best and had the most stable predictions across scenarios. The four‐category analysis is effective in determining MERNs of individual trials, and the quadratic plateau is best for determining forage winter cereal MERNs and yields at MERNs for individual trials in the north‐eastern USA.     

Effects of phosphate‐solubilizing microorganisms on strawberry yield and nutrient concentrations

Phosphorus (P)‐solubilizing bacteria and fungi can increase soil‐P availability, potentially enhancing crop yield when P is limiting. We studied the effectiveness of Bacillus FS‐3 and Aspergillus FS9 in enhancing strawberry (Fragaria × ananasa cv. Fern) yield and mineral content of leaves and fruits on a P‐deficient calcareous Aridisol in Eastern Anatolia, Turkey. The 120 d pot experiment was conducted in three replicates with three treatments (Bacillus FS‐3, Aspergillus FS9, control) and five increasing rates of P addition (0, 50, 100, 150, and 200 kg P ha^–1). Fruit yield and nutrient content of fruits and leaves and soil P pools were determined at the end of the experiment. Phosphorus‐fertilizer addition increased all soil P fractions. Strawberry yield increased with P addition (quadratic function) reaching a maximum of 94 g pot^–1 at 200 kg P ha^–1 in the absence of P‐solubilizing microorganisms. At this yield level, Bacillus FS‐3 and Aspergillus FS9 inoculation resulted in P‐fertilizer savings of 149 kg P ha^–1 and 102 kg P ha^–1, respectively. Both microorganisms increased yields beyond the maximum achievable yield with sole P‐fertilizer addition. Microorganism inoculation increased fruit and leaf nutrient concentrations (N, P, K, Ca, and Fe) with the largest increases upon addition of Bacillus FS‐3. We conclude that Bacillus FS‐3 and Aspergillus FS9 show great promise as yield‐enhancing soil amendments in P‐deficient calcareous soils of Turkey. However, moderate additions of P fertilizer (50–100 kg ha^–1) are required for highest yield.     

Boron fertilization of Mediterranean aridisols improves lucerne (Medicago sativa L.) yields and quality

Abstract

Lucerne (Medicago sativa L.) is grown as a forage crop on many livestock farms. In calcareous soils in eastern Turkey, lucerne production requires boron (B) addition as the soils are naturally B deficient. Field experiments with four B-application rates (0, 1, 3, and 9 kg ha^?1 B) were conducted in 2005 and 2006 to determine the optimum economic B rate (OEBR), critical soil test and tissue B values for dry matter (DM) production for lucerne grown on B-deficient calcareous aridisols in eastern Turkey. Boron application increased yield at each site in both years of production. The OEBR and critical soil and tissue B content were not impacted by location. Averaged over the two years and three locations, the OEBR was 6.8 kg B ha^?1 with an average DM yield of 12.0 Mg ha^?1. The average soil B content at the OEBR was 0.89 mg kg^?1 while leaf and shoot tissue B content amounted to 51.8 and 35.5 mg kg^?1, respectively. Boron application decreased tissue calcium (Ca), zinc (Zn), and copper (Cu), and increased tissue nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), iron (Fe), and manganese (Mn). Tissue and soil B increased without impacting yield at B levels up to 9 kg ha^?1. We conclude that 7 kg ha^?1 B is sufficient to elevate soil test B levels from 0.11 to 0.89 mg kg^?1 and overcome B deficiency at each of the sites in the study. Similar studies with different soils and initial soil test B levels are needed to conclude if these critical soil and tissue values can be applied across the region.     

Assessment of yield monitoring equipment for dry matter and yield of corn silage and alfalfa/grass

Whole farm evaluations have shown that accurate yield data are difficult to collect for alfalfa (Medicago sativa L.) and grass mixtures and corn (Zea mays L.) silage fields. Additionally, on-farm research, a recommended tool for adaptive management, is hindered by lack of practical ways to collect yield data. Recently, forage yield monitors have become available on self-propelled forage harvesters (SPFHs), but precision and accuracy of this technology are unknown. The objective of this project was to evaluate accuracy of yield and moisture sensing components of forage yield monitors for use in alfalfa/grass and corn silage. Moisture content, mass flow weights, total area harvested and total dry yield per hectare were measured on 11 farms in 2013; forage samples were collected for truck loads, analyzed for dry matter content, and compared to monitor-registered dry matter. Truck weights were used to compare monitor-derived yield to actual yield on two farms for alfalfa/grass and three farms for corn silage. Moisture sensors estimated crop moisture content within 3.7 % DM for alfalfa/grass and 3.0 % DM for corn silage of the oven dry value. Flow sensors estimated alfalfa/grass yield to ±0.5 and ±1.1 Mg DM/ha for corn silage. When calibrations are done regularly, forage yield monitors can provide an accurate and precise measure of dry yield for adaptive management. It is concluded that this technology can be used when plots are large and large treatment-driven yield differences are expected.     

Farmers' perspectives on slash-and-burn as a land clearing method for small-scale rubber producers in Sepunggur, Jambi Province, Sumatra, Indonesia

On September 10, 1997, Indonesian President Soeharto renewed a ban on the practice of burning forests to clear land. At that moment a thick haze caused by land-clearing related fires in Kalimantan and Sumatra, Indonesia, blanketed large parts of Indonesia, Malaysia, Singapore, Brunei, the Philippines and Thailand. These fires, aggravated by the El Niño weather pattern and described as the worst in Southeast Asian history, renewed a long-term debate on slash-and-burn (S&B) as a method of land clearing.

Acceptable alternatives to S&B should address both the problems and the benefits of the use of fire. In depth knowledge and a clear diagnosis of the problems that rise with S&B and its alternatives are needed. A social/economic/agronomic survey was therefore conducted among 37 small-scale rubber producers in Sepunggur, Jambi Province, Sumatra, Indonesia. Our objectives were to: (1) characterize S&B techniques; (2) characterize farmers' perspectives on land clearing methods related to agronomic/economic factors (soil fertility, plant growth, production); and (3) evaluate alternatives to S&B that would be acceptable to individual farmers at present and in the near future. Small rubber producers (average farm size ≈5 ha) were selected because rubber gardens are the major land use type in this area, small producers are the main contributors, and most of the forest that is presently converted for agricultural use is being planted with rubber seedings.

Farmers generally start slashing in March and burn in the month of August. Burning takes place in two steps: broadcast burn followed by pile-and-burn. The five advantages of using fire as mentioned by the farmers were: (1) burning creates space (51%); (2) ash acts as a fertilizer (23%); (3) burning improves soil structure enabling faster establishment of seedlings (15%); (4) burning reduces weed/tree competition (5%); and (5) burning reduces the occurrence of pests/diseases (3%).

Alternatives to S&B should be economically acceptable. Mulching does not provide an alternative to any of the benefits of burning. Slash-and-remove-wood addresses only the first advantage and requires a tremendous effort in labor. If forced to accept either alternative, farmers expect a reduction in income due to difficulties in establishing new rubber gardens, reductions in yield, and an increase in labor costs.

At present, small quantities of wood with economic value are sold on the local market. Slash-sell-and-burn is an alternative that could maintain the advantages of using fire while supplying the farmer with extra income and the initiative to remove and not burn the trees. Even though forest is rapidly being converted to rubber gardens, land clearing will remain in practice to rejuvenate the old rubber gardens or to convert them to other land use systems. By selling rubberwood, farmers could cover costs of land clearing and earn enough to cover some of the costs of buying higher-yielding clones for rubber planting. This alternative has benefits similar to using fire and could significantly reduce pollution problems, but a change in local trade regulations and taxes is required for its successful adoption.