The current study evaluated alternative sources of nutrients to improve the soil fertility status and yield of maize-wheat succession in Southern Brazil. The treatments were: T1: no fertilization; T2: liming with dolomitic marble; T3: alternative liming (AL) with limestone interbedded with shale; T4: AL + 50% P - with Arad natural phosphate (P-ANP) + 50% P – triple superphosphate (P-TSP); T5: AL + 100% P-ANP; T6: AL + 100% P-ANP + 100% K-rich monzogranite; T7: AL + 100% P-ANP + 100% N (50% N from tung pressed cake (N-TPC) + 50% N-urea); T8: AL + 100% P-ANP + 100% K-rich monzogranite + 100% N (50% N-TPC + 50% N-Urea) + 100% S; T9: AL + regional average rate of NPK (5-20-20) formulation. Except for T7 and T8, all treatments received the full recommended rate of N through Urea. Immediate and residual effects were evaluated over 2.5 years (90, 360 and 900 days) on soil fertility and maize - wheat yield. The limestone interbedded with shale released Ca, Mg and corrected soil acidity similarly to dolomitic marble. The fertilization strategies used in T4, T7 and T8 presented the highest cumulative productivities while T3 (U$ = 1223), T9 (U$ = 1174) and T4 (U$ = 1122) resulted in higher profits than the other evaluated fertilization strategies. The limestone interbedded with shale (T3), alone or combined with 50% of P-ANP + 50% of P – TSP (T4) provided the best economical and technical results, highlighting the potential of selected alternative regional sources for soil fertility improvement and plant-nutrients supply.

Organic matter is a key element of soil fertility. However, in-soil stocks of organic matter are in decline in specialized crop farms. Reintroducing organic fertilizers could be a way to increase or at least maintain organic matter stocks in these soils. Straw/manure exchanges between crop farms and livestock farms could improve overall land fertility and thus the long-term income of farmers. Here we used a bioeconomic model to estimate the agronomic and economic benefits of straw/manure exchanges as part of a strategy to improve soil fertility. Iterative simulations were run with prices of farmyard manure varying from €0 to €20 ton−1 to identify the price at which a crop farm can buy manure and sell straw without degrading its net income (manure ceiling price) compared to purchasing mineral fertilizer only and ploughing back straw. Parallel simulations were run to identify the price at which a livestock farmer can sell manure and buy straw without degrading its net income (manure floor price) compared to keeping all manure on the farm and buying straw on the market. The key new contributions of this study are that it (i) considers the characteristics of manure beyond its short-term fertilizing value, i.e., better mineralization of humus and a 10% increase in crop yields, (ii) estimates both the economic and agronomic benefits of manure and (iii) assesses the impacts of uncertainties on manure effects and prices. The results show that it is profitable for a French farmer in a conventional field crop system to buy manure at a price between €10 ton−1 in the short term and €18 ton−1 in the long term. The results also show that it is still economically advantageous for a livestock farmer to sell part of their manure, even at a very low price. This study shows that it is possible to better distribute manure resources over a territory in a way that enriches the soils of crop farms without degrading the soils of livestock farms.

Cassava flour is the main source of carbohydrates for family farmers in the Amazon region of Brazil. Cassava is mainly grown under shifting cultivation, in recurrent cultivation periods initiated through slash-and-burn. Its sustainability is, however, questioned due to the associated deforestation and often rapidly decreasing crop productivity. There is an urgent need to make these cassava systems more sustainable and more profitable, but we currently lack a deep understanding of the key factors governing their productivity. We conducted an on-farm study on 37 cassava fields of smallholder farmers at three locations that spanned a range of crop-fallow frequencies, some of which were initiated through slash-and-burn while others through fire-free land clearance. First, we analysed how cassava plant density at harvest was related with pedoclimatic and management factors in slash-and-burn systems. Second, we assessed the relationship between plant density and cassava root yield at harvest and conducted a yield gap analysis to better understand which factors govern cassava productivity beyond plant density in slash-and-burn systems. Finally, we compared cassava productivity between slash-and-burn and the fire-free land clearing techniques that some farmers started to adopt in the study region. Cassava yields averaged 7.2 ± 5.4 Mg ha–1 (50% of the average yield of 14.2 Mg ha–1 in the Pará State), and ranged from 0 (in case of root rot diseases) to 24 Mg ha–1. Cassava yield was associated with plant density at harvest (ranging from 0 to 10 000 plants ha–1), suggesting that managing plant density is a key determinant of the attainable yield levels. In addition, differences in cassava root yields could be largely explained by differences in labour inputs for weeding and fallow clearing, the effect of the latter depending on soil texture. Therefore, our results suggest that labour is a key production factor for cassava in the shifting cultivation systems of the Eastern Amazon in which the use of external inputs, such as chemical fertilizers and herbicides, is limited. Further, root yields were influenced by the method of field preparation, whereby yields were about 50% lower (and more variable) when fields were prepared by slash-and-burn than by mechanical ploughing or herbicide application. Despite the significantly higher yields, these alternatives to burning the vegetation are, however, still hardly adopted in Paragominas. Hence, there is a need for supporting more sustainable production systems through local and national public policies. These new systems should not only focus on soil fertility management but also on weed control and, more generally, on labour productivity.

On soils dominated by high proportions of clay and organic matter, soil acidity and poor nutrient use efficiency have a major impact on output potential. Due to the inherent chemical properties of these soils, reducing soil acidity and the prevalence of undesirable metallic cations poses challenges. As a result, these soils have a large capacity for phosphorus (P) fixation, therefore reducing plant P availability. Limestone (CaCO3 or MgCO3) is applied to agricultural soils to counteract soil acidity and reduce P fixation. The current study investigates the effects of four contrasting annual P application rates (0, 50, 100, 150 kg P/ha); split (50:50) between spring and summer, across soils with a range of soil pH values from a previous liming trial. The effect of soil pH ranges and P treatment rates on seasonal herbage growth and herbage P concentration was investigated over three years. Soil nutrient status was also investigated. Soil pH had a significant impact on the rate of mineralization and soil P concentration across each site. A soil pH of 6.2 caused a 1.8 mg/l increase in soil test P. An annual P application was necessary to maintain sufficient herbage P concentration for animal dietary requirements (0.35% DM), however there was no effect of P application or liming rate on herbage productivity across the three sites as all sites possessed sufficient soil P reserves. The current experiment has shown that despite optimal soil fertility status, ensuring sufficient plant available P is a problem on these particular soils.

Increasing yields in farmer fields is a priority to address increasing food demands. The study was conducted within four wheat-growing areas in Ethiopia: Debre Birhan, Hosaina, Sinana and Maychew. The objectives were to identify (1) best-bet soil fertility management options based on agronomic performance and economic evaluation and (2) key yield-reducing factors in farmer fields based on an agronomic survey among 55 participating farmers. Two types of on-farm experiments were conducted: researcher-managed trials that tested combinations of nutrients, including micronutrients, organic resources or both over two cropping seasons and farmer-managed trials comparing ‘improved practice’ against ‘farmer’s practice’. Fertilizer treatment affected wheat productivity in Debre Birhan (p < 0.01), a site limited in sulphur. Here, full NPK increased yields over the control (p < 0.05), whereas a combination of NPK and manure was better than the application of manure as the only source of added nutrients (p < 0.05). Applying half the recommended NPK with micronutrients and manure achieved similar yields as the full fertilizer treatment. In Hosaina, treatment had no significant effect on wheat productivity, although a combination of NPK and zinc resulted in an additional 26–57% yield relative to the other treatments. In Maychew, a significant treatment effect (p < 0.05) was observed. Here, the treatment with lower rates of nitrogen and phosphorous had lower yields than the full NPK treatment. A significant effect of plant densities on on-farm productivity was also observed. We conclude that although nutrient management including use of micronutrients is important in specific cases, investments to optimize plant densities have a huge potential to increase food productivity.

This article describes the intensification process of agriculture and its environmental limits regarding soil fertility in the rural community of Fonsagrada, in the inner region of Galicia in northwestern Spain. It addresses changes in land use, crops, and agricultural productivity between 1750 and 1890, framed within the theory of social metabolism and based on the method of nutrient balances. That technique measures nitrogen, phosphorus, and potassium flows across the landscape within a given agro-ecosystem to assess its biophysical functioning and to detect environmental constraints related to management. The intensification of cropland resulted in net losses of potassium in outlying rough grazing land and hay meadows that served as the sources of cropland nutrients. Agricultural intensification was possible due to the close stabling of livestock, which allowed for more manure availability. Doing so, however, deprived pastureland of nutrient recover through manure deposition, which created a metabolic rift in the agro-ecosystem.

In contrast to most long-settled agricultural landscapes, the US Great Plains presents a rare example of well-documented agricultural colonization of new land. The Census of Agriculture provides detailed information about evolving grassland farm systems from the beginning of agricultural expansion and then at some two dozen time points between 1880 and the present. From early sod-busting, through drought and depression, and into late-twentieth-century modernization, it is possible to track how farmers used their land in any county. Treating farmland as an agroecosystem, a hybrid human-natural landscape, this article asks how farmers captured, altered, and replenished soil fertility. Did they extract more soil nitrogen than they returned, or did they maintain a balance? The article assesses land use from a soil nutrients perspective in several plains environments to capture variation in climate (especially rainfall), native soil quality, and availability of irrigation water. It traces farm management strategies through time to understand agricultural crises, growth periods, and technological transitions in the context of soil fertility. Soil management on an agricultural frontier was markedly different from that in places that had been farmed for centuries. A shortage of people and livestock and an abundance of deep, rich soils in the plains informed farmers’ calculations as they juggled labor, capital, and market forces against family and financial strategies. Uniform methods of estimating and representing soil nutrient processes make possible a direct comparison of the relative sustainability of historical agroecosystems.

In Indonesia, management practices that reduce soil fertility could be limiting cocoa (Theobroma cacao L.) production. To address this, we investigated the effects of fertilizers and organic amendments comprising different combinations of NPK + urea, dolomite, and manure-based compost on soil properties and cocoa productivity. We extended an existing field experiment in South Sulawesi, Indonesia, to assess these treatments’ effects on cocoa trees from the age of 2.9 years to 7.4 years. The treatments were first applied 5 months after planting and subsequently twice a year. Soil analyses were performed before planting, after 3 years, and finally after 7 years. Productivity was assessed yearly between the age of 3.5 and 7.4 years. The highest yields were obtained from the plots receiving compost, although the yield benefits diminished over time. Inorganic fertilizer alone doubled the yield compared to the control, while the yields with compost and compost + fertilizer were three times that of the control. With dolomite alone, the yield cumulated over 4 years was 41% higher than the control. The positive effect of compost on cocoa yields can potentially be attributed to (1) physical changes increasing soil water availability, (2) the chemical improvement of nutrient availability, and (3) biologically, by promoting the activity of beneficial organisms. The application of dolomite increased soil pH, Ca, and Mg contents. Soil organic carbon greatly declined in the composted treatments, even though 10 kg of compost was applied per tree per year, probably because of the low C:N ratio of the compost. Future studies should assess different fertilizer formulations and combinations with organic inputs and explore the mechanisms by which compost promotes cocoa productivity.

To exploit the potential of ecological intensification during sunflower cropping, it is crucial to understand the potential synergies between crop management and ecosystem services. We therefore examined the effect of pollination intensification on sunflower yield and productivity under various levels of soil fertilization over two seasons in the eastern Free State, South Africa. We manipulated soil fertility with fertilizer applications and pollination with exclusion bags. We found a synergetic effect between pollination and soil fertilization whereby increasing pollination intensity led to a far higher impact on sunflower yield when the soil had been fertilized. Specifically, the intensification of insect pollination increased seed yield by approximately 0.4 ton/ha on nutrient poor soil and by approximately 1.7 ton/ha on moderately fertilized soil. Our findings suggest that sunflower crops on adequate balanced soil fertility will receive abundant insect pollination and may gain more from both synergies than crops grown in areas with degraded soil fertility.

Soil acidity and poor nutrient use efficiency are major limiting factors as regards output potential on heavy soils, soils which are dominated by high proportions of clay and organic matter, with impeded drainage, high buffering capacity and located in high rainfall areas. Lime is applied in order to counteract these limiting factors and in turn improve agricultural output and productivity. The current study investigates the effects of two commonly used lime products at three comparable treatment rates, ground lime (7.5, 5 and 2.5 tonne/ha) and granulated lime (7.5, 2.5 and 1.5 tonne/ha), applied across three distinct sites. The ability of each lime product and treatment rate to counteract soil acidity, increase nutrient availability and influence soil physical structure was assessed over time. On average across sites, 1 tonne/ha of each lime product increased soil pH by 0.15 and 0.21 pH units between ground and granulated lime, respectively. Site 3 experienced the greatest increase change in soil pH in comparison to the other two sites, largely due to lower clay content and cation exchange capacity. Granulated lime was 5.7 times more expensive than ground lime in its ability to reduce soil acidity. The high treatment rate showed the greatest reduction in soil acidity, aluminium and iron concentration as a mean across all sites. Morgan's soil test phosphorus concentration increased across all sites, with treatment rates having no effect on the rate of increase. There was evidence of reduced soil compaction and lime application showed no negative implication on soil physical structure.

Unlike well-known global patterns of plant species richness along altitudinal gradients, in the mountainous areas of the Brazilian Caatinga, species richness and diversity reach their maxima near mountain tops. The causes of this unusual pattern are not well understood, and in particular the role of edaphic factors on plant community assembly along these gradients has not been investigated. Our goal was to assess the role of edaphic factors (fertility and soil texture) on plant community composition and structure on two mountains of the Brazilian semi-arid region. In 71 plots (Bodocongó site, twenty-one 200-m2 plots, 401–680 m asl; Arara site, fifty 100-m2 plots, 487–660 m asl) we recorded 3114 individuals representing 61 plant species; in addition, at each plot we collected composite soil samples from 0–20 cm depth. Significant altitude-related changes were observed both for community structure and composition, and edaphic variables. A canonical correspondence analysis allowed the distinction of two groups of plots according to species abundances, indicating a preferential habitat distribution of species depending both on altitude and soil variables. Although soil fertility was lowest at the highest altitudes, these areas had high richness and diversity. Conversely, the more fertile foothills were characterized by the dominance of generalist pioneer species. Despite the relatively short altitudinal range that characterizes the studied mountains, this study elucidates the role of edaphic factors on the floristic composition and species richness patterns on the mountains of the Brazilian semi-arid region.

Mugwort (Artemisia vulgaris L.) is becoming increasingly problematic in cool-season pastures and grasslands. A 3-yr field experiment evaluated different rates of nitrogen and herbicides for A. vulgaris management in a permanent grassland. The main plot had three nitrogen rates, 0, 62, and 124 kg N ha−1; the subplot had three herbicides, aminopyralid, clopyralid, and glyphosate; and the sub-subplot had three herbicide rates, aminopyralid (61, 122, and 244 g ae ha−1), clopyralid (140, 280, and 560 g ae ha−1), and glyphosate (552, 1,104, and 2,208 g ae ha−1). Results revealed that nitrogen had no effect on A. vulgaris control, rhizome biomass, and stem density. However, cool-season grass biomass was the highest (7,126 kg ha−1) in the plots that received 124 kg N ha−1 and 244 g ae ha−1 of aminopyralid. Only glyphosate caused grass injury, which varied from 65% to 100% depending upon application rate. By 9 mo after initial herbicide treatment (MAIT), A. vulgaris was controlled 60% to 98% with aminopyralid at ≥61 g ae ha−1 or glyphosate at ≥552 g ae ha−1. By 21 MAIT, aminopyralid at ≥122 g ae ha−1 or glyphosate at ≥1,104 g ae ha−1 resulted in >95% reduction in A. vulgaris stem density and rhizome biomass and provided ≥98% visual control. By 33 MAIT, complete control of A. vulgaris was confirmed in plots treated with aminopyralid at ≥122 g ae ha−1 or glyphosate at ≥1,104 g ae ha−1. Clopyralid was not effective; A. vulgaris control was <40% even after three annual applications at 560 g ae ha−1. Results indicate that integration of nitrogen fertilization with aminopyralid did not improve A. vulgaris control, but was advantageous in enhancing cool-season grass productivity.

The cotton-wheat double-cropping system is widely used in the Yellow River Valley of China, but whether and how different planting patterns within cotton-wheat double-cropping systems impact heat and light use efficiency have not been well documented. A field experiment investigated the effects of the cropping system on crop productivity and the capture and use efficiency of heat and light in two fields differing in soil fertility. Three planting patterns, namely cotton intercropped with wheat (CIW), cotton directly seeded after wheat (CDW), and cotton transplanted after wheat (CTW), as well as one cotton monoculture (CM) system were used. Cotton-wheat double cropping significantly increased crop productivity and land equivalent ratios relative to the CM system in both fields. As a result of increased growing degree days (GDD), intercepted photosynthetically active radiation (IPAR), and photothermal product (PTP), the capture of light and heat in the double-cropping systems was compared with that in the CM system in both fields. With improved resource capture, the double-cropping systems exhibited a higher light and heat use efficiency according to thermal product efficiency, solar energy use efficiency (Eu), radiation use efficiency (RUE), and PTP use efficiency (PTPU). The cotton lint yield and biomass were not significantly correlated with RUE across cropping patterns, indicating that RUE does not limit cotton production. Among the double-cropping treatments, CDW had the lowest GDD, IPAR, and PTP values but the highest heat and light resource use efficiency and highest overall resource use efficiency. This good performance was even more obvious in the high-fertility field. Therefore, we encourage the expanded use of CDW in the Yellow River Valley, especially in fields with high fertility, given the high productivity and resource use efficiency of this system. Moreover, the use of agronomic practices involving a reasonably close planting density, optimized irrigation and nutrient supply, and the application of new short-season varieties of cotton or wheat can potentially enhance CDW crop yields and productivity.

The debate on the land–poverty nexus is inconclusive, with past research unable to identify the causal dynamics. We use a unique global panel dataset that links survey and census derived poverty data with measures of land ecosystems at the subnational level. Rainfall is used to overcome the endogeneity in the land–poverty relationship in an instrumental variable approach. This is the first global study using quasi-experimental methods to uncover the degree to which land improvements matter for poverty reduction. We draw three main conclusions. First, land improvements are important for poverty reduction in rural areas and particularly so for Sub-Saharan Africa. Second, land improvements are pro-poor: poorer areas see larger poverty alleviation effects due to improvements in land. Finally, irrigation plays a major role in breaking the link between bad weather and negative impacts on the poor through reduced vegetation growth and soil fertility.

High yields and crop quality in organic small grain production can only be achieved through successful management of nitrogen. Experienced farmers and advisors in the Northeastern U.S. were asked to discuss the most pressing challenges in organic nitrogen management for organic small grain systems, with a particular focus on legume green manures (LGMs). Eighteen semi-structured interviews with 12 farmers and eight advisors were conducted between December 2017 and March 2018. The farmers employed a range of materials and practices for fulfilling the nitrogen fertility needs of their crops, including LGMs, animal manures and organic fertilizers. Farmers and advisors identified cost, overdependence on external nitrogen sources, nitrogen source access, diversifying rotations, weed management and predicting nitrogen mineralization of organic residues as major challenges in nitrogen management. Results indicated that cost-effectiveness in nitrogen management is essential, but that farmers consider additional factors, such as weed pressure and long-term soil health effects, when choosing nitrogen sources or practices. Legume-based nitrogen fertility is promising for small grain systems in this region, but structural challenges, such as the lack of animal agriculture proximal to grain operations, and limited cash crop markets, impede the development of diverse rotations that feature long-term legume sods. Recommendations include additional field-based research, including on-farm, participatory LGM studies as one avenue. Programming and educational outreach should focus on bolstering farmers' understanding of nitrogen mineralization of incorporated LGM residues, as well as their ability to anticipate and respond to sources of variability in LGM systems.

Sustainability of cereal-based cropping systems remains crucial for food security in South Asia. However, productivity of cereal–cereal rotations has declined in the long run, demonstrating the need for a sustainable alternative. Base crop, that is, common crop in different crop rotations, productivity could be used as a sustainability indicator for the assessment of different long-term crop rotations. This study aimed to evaluate the impact of grain legume inclusion in lowland rice–wheat (R-W) and upland maize–wheat (M-W) rotation on system’s base crop (rice in lowland and wheat in upland crop rotations) productivity and sustainability and also in soil fertility. Mung bean (April–May) inclusion in R-W rotation increased rice grain yield by 10–14%. In upland, mung bean inclusion in M-W rotation increased wheat grain yield by 5–11%. Replacing wheat with chickpea in R-W rotation increased rice grain yield by 5–8%. Increased base crop productivity in legume inclusive rotations was attributed to significant improvement in panicle (rice) or spike (wheat) attributes. Increased soil organic carbon and available nitrogen and phosphorus in the legume inclusive rotations significantly influenced the base crop productivity in both the production systems. Among the crop rotations, R-W-Mb (in lowland) and M-W-Mb (in upland) rotations had the highest system productivity and net return. Therefore, intensification/diversification of cereal–cereal rotations with grain legume could improve soil fertility and sustain crop productivity.

In recent decades, a diverse community of dairy farmers, consumers and nutrition advocates has campaigned amidst considerable government opposition, to secure and expand the right of individuals to produce, sell and consume fresh unprocessed milk, commonly referred to as ‘raw milk’. This advocacy shares important parallels with battles fought in the organic food movement over the past century. Both the raw milk and organic food movements originated with farmers and consumers who sought to replace industrialized food production and processing practices with more traditional ones. Both movements equate the preservation of natural integrity in farming and food handling with more wholesome, nutritious food and environmental conservation. Both movements have had to work diligently to overcome a false perception that their practices are anachronistic, notably with regard to productive output of organic agriculture and the safety of fresh unprocessed milk. There is also the failure of opponents to acknowledge a growing body of scientific evidence for health benefits associated with drinking of fresh unprocessed milk. The raw milk movement has the potential to economically benefit family farmers, much as organic agriculture has done. Building soil fertility, a foundational principle of organic farming, would benefit from having numerous small pasture-based dairies spread across the land providing fresh unprocessed milk. Agricultural universities and the Cooperative Extension System could seize a real leadership opportunity by promoting and participating in this reinvention of dairy farming, and restoring the ecology of this traditional food and farming system.