Cultivated Plots Research Articles

OMERE: A Long‐Term Observatory of Soil and Water Resources, in Interaction with Agricultural and Land Management in Mediterranean Hilly Catchments

Core Ideas OMERE is a Mediterranean observatory of two farmed catchments in Tunisia and France. Water, contaminant, and erosion fluxes are monitored from plot to catchment scales. Soils and land use in relation with agriculture are surveyed. Scientific results concern elementary processes and integrated catchment functioning. Models were conceived for evaluation of land use and agricultural management scenarios. To account for the diversity of agricultural and ecosystem situations in hilly Mediterranean areas, the agro‐hydrological observatory OMERE (Observatoire Méditerranéen de l'Environnement Rural et de l'Eau) monitors two farmed catchments—one in northern Tunisia and the other in southern France. Mediterranean regions are typified by a highly variable climate, with an alternation of long droughts and intense storms, and by a strong heterogeneity of soil properties, due to a combination of climate, relief, parent materials, sparse vegetation, intense land use, man‐made infrastructure (ditches, terraces, etc.), and agricultural activities. In this context, OMERE aims to document the impacts of agricultural and land management on mass fluxes in Mediterranean farmed headwater catchments. The observation strategy is motivated by monitoring water, sediment, and contaminant fluxes and hydrologic and climatic variables at different spatial scales from cultivated plots and landscape elements to the catchment scale. These measurements have been performed at a fine time resolution over a long‐term scale and by surveying land use, agricultural practices, and soil surface characteristics. The long‐term observation strategy intends to support integrative multidisciplinary research for elucidating the conditions that improve soil and water management and delivery of ecosystem services in a Mediterranean rainfed cultivated context. The observatory has led to scientific insights regarding three scientific objectives: (i) to better understand the fluxes of water, erosion, and contaminants, especially pesticides, and of their natural and anthropogenic drivers on short‐ and long‐term scales; (ii) to analyze the aggregate effects of farming and land management on mass fluxes across scales, from plot to catchment or landscape scales; and (iii) to derive new scenarios for sustainable agricultural management and improved delivery of ecosystem services.

From weeds to wheat: a diachronic approach to ancient biocultural diversity in the Santa María valley, northwest Argentina

The aim of this paper is to analyse continuities and changes in plant diversity and use in the southern part of the Santa Maria valley in northwest Argentina, from the 1st millennium ad up to the Spanish Conquest in the 16th century. Variable degrees of association between people and plants (wild, weedy and domesticated), as well as various management practices (gathering, cultivation, tolerance, eradication, protection and encouragement) were studied to investigate the biocultural history of this region through the analysis of plant macroremains from archaeological sites. Samples were obtained from four archaeological sites located in the valley, Rincon Chico 1, Rincon Chico 15, Soria 2 and El Colorado. As a result, we identified 628 macroremains belonging to 20 taxa and determined whether they were either wild plants, weeds or crops, related to strategies of gathering and cultivation. The results suggest that there were changes through time, with a dominance of ruderal weeds in the earliest of the archaeological sites along with a diversity of association degrees, while a division was found between wild and domesticated plants, represented by maize and Prosopis (algarrobo), in the sites of the Late period. This last scenario suggests that the growing of trees and shrubs together with crops and pasture (agroforestry), or woodland management together with grazing (silvopasture), could have been part of the past land management practices in the area. Chenopodium remains indicate past complexes of wild plants, weeds and crops growing together in the cultivated plots; the newly introduced crops brought from Spain, such as wheat and barley, did not replace the local plants, mainly Prosopis (algarrobo) and Zea mays (maize), which were still grown during early colonial times. This paper offers a diachronic perspective on plant management in a particular region, considering a plant record that is still limited, but which allows us to get a first glimpse of how plant management strategies may have changed in this part of South America.

3D plant model assessed by terrestrial LiDAR and hemispherical photographs: A useful tool for comparing light interception among oil palm progenies

The paradigm of functional-structural models (FSPM) assumes that studying the detailed organisation of plant structure allows a better understanding of functional processes; in particular the way plants capture light for performing photosynthesis. However, much attention must be paid toward the consistency between virtual plants and plants in the field in terms of size and geometry to accurately evaluate light interception. This paper thus aimed at i) assessing the capacity of a 3D architectural model based on oil palms (Elaeis guineensis) to accurately represent plants structural characteristics at both the scale of the individual plant and the cultivated plot and ii) employing the validated 3D mock-ups to investigate how light interception efficiency varies among progenies that exhibit different architectures. Innovative indicators related to plant geometry and topology were derived from terrestrial LiDAR scanners (TLS) and hemispherical photographs (HP) in order to assess a 3D plant model. Indicators such as plant height, width and volume, gap fractions and solid angle projections were established from field measurements and were compared to equivalent indicators that had been extracted from virtual TLS (VTLS) and virtual HP (VHP) simulated on 3D mock-ups. Indicators were then evaluated for their significance in terms of light interception. Progeny effect on light interception efficiency was finally evaluated for five progenies.The structural indicators estimated from VTLS and VHP were significantly correlated with equivalent indicators estimated from TLS and HP, respectively, and with simulated outputs related to light interception. Light interception efficiencies estimated from validated 3D mock-ups differed significantly among the five progenies under study, most notably along plant development.Our results highlight the relevance of combining TLS- and HP-derived indicators to evaluate the reliability of virtual 3D reconstruction of plants in relation to light capture, at both the plant and plot scales. The study paves the way for further investigations aiming at unravelling the relationships between oil palm architecture and the physiological processes driving its production.

Glyphosate Efficacy as Influenced by Cultivation Practices on a Creeping Bentgrass Fairway Turf

Glyphosate is routinely used to eradicate existing turf in golf course fairway renovations. However, current label recommendations suggest delaying cultivation of glyphosate treated areas for 7 days. A 2-year field study was conducted to assess how various seedbed preparation techniques (i.e., verticutting, core-cultivation, or verticutting + core-cultivation) influence glyphosate efficacy on creeping bentgrass fairway turf when completed at various intervals shortly after application [0–7 days before cultivation (DBC)]. Percent green cover declined from initial values of ≈90% to ≤0.2% at the end of the study after glyphosate application at all timings, regardless of cultivation during both years. All cultivated plots had 37.9% to 72.3%, or 5.9% to 62.1% less green cover compared with noncultivated plots when glyphosate was applied ≤3 days before cultivation in 2014 and 2015, respectively. Generally, the number of days until green cover reached 1% (GC1) ranged from 6.6 to 11.1 in 2014 and 5.2 to 6.9 in 2015. Within glyphosate application timings, no differences in GC1 were observed between cultivated and noncultivated treatments in 2014, except at 0 DBC. The GC1 for verticutting was 5.1 days longer than noncultivated plots; however, all other cultivation treatments were equivalent to noncultivated plots when glyphosate was applied 0 DBC. All cultivation treatments reduced GC1 1.7 to 2.5 days compared with the no cultivation treatment, regardless of glyphosate application timing in 2015. Results from this study indicate that cultivation of creeping bentgrass fairway turf within 7 days of glyphosate application is not detrimental to long-term herbicide efficacy, and in some cases may actually enhance the rate of decline of glyphosate treated creeping bentgrass.

CARACTERIZAÇÃO DO CULTIVO E CONSERVAÇÃO DA AGROBIODIVERSIDADE EM LOTES URBANOS VAGOS EM DUAS PEQUENAS CIDADES NO ESTADO DE SÃO PAULO

<p>A agricultura urbana e periurbana (AUP) é um fenômeno mundial crescente e traz uma gama de benefícios, como a busca da segurança alimentar e nutricional, geração de renda e a possibilidade de conservação de agrobiodiversidade <em>on farm</em>. No Brasil, cidades de pequeno porte e zonas periféricas de metrópoles ainda apresentam características rurais, como espaços intersticiais desocupados, possibilitando a ex-moradores das zonas rurais a manutenção do hábito de plantar. O objetivo deste estudo foi descrever a agricultura urbana praticada nos lotes vagos em duas cidades do interior do estado de São Paulo, Charqueada (CH) e Santa Gertrudes (SG), abordando os seguintes aspectos: caracterização socioeconômica dos entrevistados; caracterização dos lotes quanto a posse, tempo de cultivo e manejo agrícola; e registro das plantas e variedades cultivadas, com ênfase nas raízes e tubérculos, com vistas a avaliar o potencial para a conservação de agrobiodiversidade <em>on farm</em> nesses espaços. Todos os lotes cultivados na malha urbana foram georreferenciados, para o estabelecimento de uma amostra geral (77 em CH e 43 em SG) para a caracterização da população quanto a aspectos socioeconômicos e relativos à agricultura praticada. Posteriormente, selecionou-se uma subamostra (30 em CH e 20 em SG), para inventário das plantas cultivadas. Os levantamentos foram realizados por meio de entrevistas estruturadas e semi-estruturadas, utilizando-se a turnê guiada nos lotes para o levantamento das plantas. Os agricultores são na grande maioria homens acima de 50 anos de idade, de baixa renda e baixa escolaridade; não há participação efetiva dos jovens. Há uma presença importante de migrantes de outros estados, nordestinos em CH e mineiros em SG. Levantaram-se 102 etnoespécies de plantas cultivadas, principalmente alimentares, sendo as mais frequentes (>40% dos lotes em ambas as cidades) mandioca, mamão e quiabo. Vários cultivos apresentaram etnovariedades, mas o conhecimento dos agricultores sobre as mesmas não é muito aprofundado. A agrobiodiversidade levantada atesta o potencial da agricultura urbana para conservação <em>on farm</em>, porém o desinteresse dos mais jovens e as pressões de ocupação imobiliária do solo urbano podem dificultar sua continuidade. Há necessidade de políticas públicas que ordenem a atividade e garantam um mínimo de estabilidade, bem como da conscientização da população em geral sobre o papel e a importância da conservação da diversidade agrícola. </p>

CARTOGRAPHIE DE LA DYNAMIQUE DE TERROIRS VILLAGEOIS À L’AIDE D’UN DRONE DANS LES AIRES PROTÉGÉES DE LA RÉPUBLIQUE DÉMOCRATIQUE DU CONGO

Les aires protégées de la République démocratique du Congo (RDC) sont mena-cées par diverses pressions anthropiques nécessitant un suivi fréquent et précis. Le mini-drone Falcon équipé d’un appareil photo numérique Sony NEX-7 a été utilisé pour cartographier et suivre la dynamique d’un terroir villageois dans le Domaine de chasse de Mondo Missa à l’est du Parc national de la Garamba, au nord-est de la RDC. Un total de 3 143 photos acquises en avril et juillet 2015, avec une résolution au sol de 8 cm/pixel, a été orthorectifié. La cartographie a porté sur une zone de 114 ha. Les ortho-images ont d’abord été segmentées, les segments étant ensuite classés manuellement par photo-interpré-tation. Des changements notables ont été constatés entre les deux dates. Les zones des forêts et savanes ont perdu 6,5 ha (86,6 à 80,1 ha). Les jachères sont pas-sées de 16,9 à 8,2 ha, les défriches de 4,1 à 10,0 ha. Les cultures saisonnières ont connu une variation allant de 3,2 à 11,8 ha. La taille moyenne des parcelles cultivées est de 0,2 ha (s = 0,14 ha ; n = 50). Enfin, la surface occupée par les arbres isolés a peu évolué (de 1,3 à 1,9 ha), celle des implantations humaines étant constante (1,7 ha). Ces résultats traduisent le fait que l’expansion de l’agriculture itinérante sur brûlis induit une conversion des habi-tats naturels et une modification de la composition végétale. Les aéronefs sans pilote à bord permettent de réaliser une cartographie précise et une surveillance rapide des changements d’affectation des terres à petite échelle dans les aires pro-tégées des forêts et savanes tropicales. Ils offrent donc une solution efficace pour évaluer la déforestation et la dégradation au sein des espaces occupés par les com-munautés locales. Cette évaluation repré-sente un enjeu important dans le proces-sus REDD+ qui envisage de quantifier avec précision ces évolutions.

Impact of lithology and soil properties on abandoned dryland terraces during the early stages of soil erosion by water in south-east Spain

Soil erosion by water in abandoned dry terraces is one of the most important environmental problems in semiarid areas, enhancing biological degradation and reducing possible resources that can be obtained. However, little is known about the effects of the types of lithology and soil properties on the early stages of soil erosion. Therefore, the main aim of this research was to assess the effect of different lithologies (marls, limestones, and metamorphic—phyllites, schists, and greywackes—materials) and soil properties on the early stages of soil erosion by water in abandoned dry terraces, compared with similar terraces still in agricultural use. Soil analyses (texture, aggregate stability, and bulk density) and 22 rainfall simulations were carried out under dry conditions. During the experiments, local inclination, vegetation and stone cover, total organic matter, and antecedent soil moisture were also quantified. The results showed that the highest soil loss (41.41 g/m2 in cultivated plots and 17.05 g/m2 in the abandoned plots) and runoff (3.79 L/m2 in the abandoned plot) occurred on marl substrata. Marls also showed the shallowest infiltration front (9 cm) and lowest infiltration rate (4.3 cm/min). Limestones and, especially, metamorphic areas, showed a lower degree of soil erosion, higher infiltration rates, and deeper infiltration fronts.

Phytostabilization of salt accumulated soil using plant and biofertilizers: Field application

This field study aimed to evaluate the plant growth-promoting potential of biofertilizers. Plant growth-promoting rhizobacterium Arthrobacter scleromae SYE-3 were isolated from local plants grown in saline soil, and isolates were applied as biofertilizers to evaluate growth-promotion effects on lettuce, radish, and Chinese cabbage in cultivated plots (100 m2) of salinized soil. Strain produced 89.15 ± 0.36 mg/L indole-3-acetic acid on day 3 of incubation, and 1-aminocyclopropane-1-carboxylate deaminase activity was 0.20 ± 0.06 OD at the end of the incubation period (after 72 h). After 102 days of cultivation, SYE-3 increased shoot lengths by 23.5%, 48.3%, and 19.5% in experimental lettuce, radish, and Chinese cabbage, respectively, compared with controls. Leaf number increased in lettuce only, by 45.1%. The viable cell count of SYE-3 was maintained during the vegetation restoration period. These results indicate that can serve as a promising microbial inoculant for improving plant growth and therefore enhancing yield in salinized environments, likely through raising plant growth promoting efficiency.

Interaction of land use, slope gradient and rain sequence on runoff and soil loss from weakly aggregated semi-arid soils

The effects of land use, tillage methods and slope gradient on soil erosion have been widely investigated. However, there is limited information about their effects on very weakly aggregated soils that can be found in semi-arid, nutrient limited regions of low productivity. This study was carried out to investigate the interaction of land use, tillage method and slope gradient on runoff and soil loss in a weakly aggregated soil in the north-west of Iran. Plots (3m×10m) with three treatments and two replicates were installed in each of four slopes gradient categories (12.6, 15.3, 17.0, 19.4%). The three treatments were pasture with poor vegetation cover (27%) and rainfed wheat either cultivated up to down slope or along the contour. Wheat was sown in early autumn and runoff and soil loss was measured under natural rainfall during the eight months long growing period. Out of 53 precipitation events, 8 storms were classified erosive. The susceptibility of all plots to produce runoff and soil loss increased pronouncedly and highly significantly with subsequent rainfalls. The potential of a rainfall to produce runoff and soil loss was thus highly dependent on preceding rainfalls. Wheat cultivation increased runoff 13 times and soil loss 60 times compared to pasture. Runoff and soil loss increased about 5.5 and 35 times in plots cultivated up to down slope as compared with contour cultivated plots. The effects of land use increased pronouncedly with increasing slope gradient. These results showed that erosivities of rainfalls separated by several months were not independent from each other and that the effects of land use and slope gradient interacted. Also the effect of slope gradient on soil loss was much larger than estimated by current equations. All effects could be explained by the extremely weak aggregates. Soil erosion was thus not detachment limited but transport limited. Transport limitation decreased in the sequence of rainfalls due to loss of surface roughness and with increasing slope gradient due to increasing failure of roughness elements. Under conditions leading to extremely weak soil aggregates, land use and slope gradient thus exert a much larger impact on runoff and soil loss than what is commonly assumed. This should be better considered in soil conservation efforts but also in runoff and erosion modelling.

Invertebrate Biomass and Richness in Various Food Plot Types in East Texas

As northern bobwhite (Colinus virginianus) chicks are dependent on invertebrates for food, land managers often use spring/summer food plots to meet these needs. We examined invertebrate production in native vegetation and 6 different food plot types (i.e., fallow disking only; fallow disking and fertilizing; or disking, fertilizing, and planting a single species [browntop millet, iron and clay peas, or sorghum] or a multi-species mix [browntop millet, catjang peas, iron and clay peas, Japanese millet, and pearl millet]) in the Pineywoods of east Texas. Invertebrates were collected weekly during the summers of 1997 and 1999 and for 5 weekly sampling periods during summer, 1998. For each food plot type, invertebrates were separated from debris, air dried, and weighed as a group. Bi-weekly, a 100-invertebrate sub-sample was randomly selected from each sample and sorted to order with weight and number of individuals recorded. When spring precipitation was sufficient, multi-species food plots produced greater (P < 0.05) invertebrate biomass than fallow or native vegetation plots, and all cultivated plots had more (P < 0.05) biomass than native vegetation. Likewise, all cultivated plots had more (P < 0.05) biomass than fallow plots in early summer but not in mid- and late summer. A combination of multi-species (with legumes) food plots and fallow disking should provide bobwhite chicks with invertebrates throughout most summers.

Particle Size Distribution, Soil Organic Carbon Stock and Water Retention Properties of Some Upland Use System of Odisha and Assessing their Interrelationship

Analyzed particle size distribution, soil water retention properties and organic carbon (SOC) stock of some upland cropping/land use systems of a watershed of Odisha (Kadalipal watershed, Dhenkanal, Odisha) viz., forest grazing land, maize, rice, groundnut, cucumber, okra, cowpea, cashew nut plantation and barren land and assessed their interrelationship. An overview of soil texture of the samples revealed that sandy clay loam texture constituted about 60% of all samples in different cropping systems and at different depths. Clay loam, sandy loam and loamy texture represented 20, 15 and 5%, respectively. Bulk density (BD) of surface layer ranged from 1.39 Mg m−3 in C7 (cashew plantations) to 1.48 Mg m−3 in forest grazing land (C0). The average clay content in the soil profile ranged from 23.8% in C0 (grazing land) to 32.6% in C6 (cowpea). The SOC at surface (0–0.15 and 0.15–0.30 m) layers were higher in forest grazing land (9.6 to 10.8 g kg−1) and inside cashew plantation (12.3 to 13.5 g kg−1) whereas, SOC was low in crop cultivated plots. Continuous tillage and cultivation of nutrient exhaustive crops might have favoured rapid rate of mineralization than that of accumulation of SOC in these fields. Among crop fields, legumes (groundnut, cowpea) hold promise for greater accumulation of SOC in the long-term. Soil water retention was found to be significantly correlated with SOC at 0–0.15 m depths only rather than the SOC of whole profile. Soil pH, BD, porosity had significant relationship (P< 0.05) with SOC content.

Detection and genome characterization of &lt;i&gt;Potato virus&lt;/i&gt; Y isolates infecting potato (&lt;i&gt;Solanum tuberosum&lt;/i&gt; L.) in La Union (Antioquia, Colombia)

Potato virus Y (PVY) is one of the most severe viruses affecting the production of potato (Solanum tuberosum) in the world. This study presents a detailed molecular analysis using nextgeneration sequencing (NGS), IC-RT-qPCR and RT-PCR on the PVY isolates infecting seed-tubers and foliage of potato plants cv. Diacol-Capiro in La Union (Antioquia, Colombia). Analysis of incidence by IC-RT-qPCR in 15 random leaf samples of three cultivation plots and fifteen sprouting tuber eye-buds reveal infection levels between 13.4 and 80%; a higher incidence of 86.7% was observed in seed-tuber samples with threshold cycle (Ct) values as low as 24.3. Genome assembly from a bulk of foliage samples resulted in a consensus PVY genome (PVY_LaUnionF) of 9,702 nt and 399 polymorphic sites within the polyprotein ORF; while the assembled genome from sprouts of tubers has 9,704 nt (PVY_LaUnionT) and contained only six polymorphic nucleotide sites. Phylogenetic analysis demonstrates that the PVY isolates from leaf samples are in the recombinant PVYNTN group (sequence identity &gt;99%); while those from tuber sprouts are in the PVYN/NTN group with identities above 95%. Sanger sequencing of viral capsid suggests the presence of a third variant related to PVYO, a prevalent strain reported in potato fields worldwide.

Effects of inorganic amendments, rice cultivars and cultivation methods on greenhouse gas emissions and rice productivity in a subtropical paddy field

With the rapidly increasing demand of rice globally, there is an urgent need to develop management strategies to improve the yields of rice crops, while at the same time minimize the possible adverse climatic impacts arising from greenhouse gas emissions from paddy fields. In this study, we investigated the influence of amendment application (steel slag and sulfate), rice cultivars (super rice cultivar, Qiuyou 6, and common rice cultivar, Hesheng 10), and cultivation methods (hand cultivation, machine cultivation, throwing cultivation) on rice yield, soil properties, as well as CH4 and N2O emissions in a subtropical paddy field in southeast China. When compared to the controls, mean CH4 emissions were significantly lower in the steel slag amendment and sulfate amendment plots by 66.1% and 23.1%, respectively, but significantly higher in the machine cultivation plots by 26.6% (P<0.05). On the other hand, we observed significantly higher mean N2O emissions from the super rice, machine cultivation, and throwing cultivation plots than those from the controls by 133.4%, 45.8%, and 172.2%, respectively (P<0.05). When taking into the account both CH4 and N2O emissions, the total global warming potential per unit yield was significantly lower in the plots amended with steel slag and sulfate than in the controls. Moreover, we found that steel slag application, machine cultivation and throwing cultivation were able to increase crop yield significantly (P<0.05). Our findings suggest that a combination of steel slag application and modernized cultivation methods, in particular throwing cultivation, would be effective in improving crop yields and mitigating greenhouse gas emissions from the subtropical paddy fields.

Responses of ammonia-oxidizing bacterial communities to land-use and seasonal changes in Mollisols of Northeast China

In this study, AOB community was investigated over a 2-year period in cultivated Mollisols (0–20 cm) with three fertilizer treatments [no fertilizer (NoF), chemical fertilizer (CF) and chemical fertilizer plus manure (CFM)] and in an adjacent plot under natural restoration (NR). The crop rotation of maize, soybean and wheat was repeated every three years. The NR plot was abandoned agricultural land that was naturally revegetated with grasses. The AOB communities were characterized by clone sequencing of amoA gene targets, which encode ammonia monooxygenase subunit A. Phylogenetic analyses showed that the AOB communities in the Mollisols of Northeast China were related to defined groups, including clusters 1, 2, 3a, 3b, 9, and 10 in Nitrosospira and cluster 7 in Nitrosomonas. Nitrosospira cluster 3 was the most frequently recovered AOB in all treatments, and cluster 3a.2 and 3a.2-related sequences were common in cultivated soils. However, 12–27% of sequences were not related to any known AOB species, indicating a high diversity of AOB communities in Mollisols. There was a distinct AOB community in the NR plot and the cultivated plots, consistent with the hypothesis that land-use alters AOB community, and this appeared to be related to the soil pH. Cultivated soils with added N fertilizer had a greater frequency of clones in the Nitrosospira cluster 10 sequence type, but suppressed clones in the Nitrosospira cluster 3a.1 sequence type, whereas Nitrosomonas sequences were only recovered from the CFM treatment. The AOB clone frequency differed between the growing and non-growing seasons, possibly because the AOB communities were favoured by warm, moist soil conditions or the active plant rhizosphere during the growing season. The ecological implications of land-use change and seasonality on the contribution of these diverse AOB communities to primary production in Mollisols merits further attention.

Effects of Management Practices on Soil Nutrient Levels in Sabke Catchment Area, Nigeria

In Nigeria’s drylands, profitable crop production requires adequate soil fertility management. This study examines the effects of farmer-managed practices on soil fertility in Sabke catchment of the drylands. Seven sites under permanent cropland, fallow land, grassland, shrubland, orchard land, intercropping land and woodland distributed on four transects were selected across the catchment. At every site, five replicate soil samples were collected from 0-15cm (topsoil) and 20-30cm (subsoil) and analysed for C, N, P, Ca, Mg, K and Na. Higher topsoil values of most of the properties were observed under cropland and intercropping sites. The two cultivated plots receive annual applications of organic manure in addition to chemical fertilizer and crops residue retention while the other plots are not. Thus, improvement in soil organic matter and nutrients would be expected in soils of the area with high rate of application of manure and chemical fertilizer, and retention of crop residues

Sustainable use of natural resources for crop intensification and better livelihoods in the rainfed semi-arid tropics of Central India

In Indian semi-arid tropics (SAT) in general and central part i.e. Madhya Pradesh state specifically; there are large yield gaps in most of the rainfed crops between current farmers’ yields and achievable ones. Soil fertility related degradation due to deficiencies of secondary and micronutrients mainly sulphur, boron and zinc in addition to macronutrients is mainly responsible for poor crop productivity, and along with poor hydraulic properties of Vertisols is responsible for about 2 million ha rainy season fallows. Soil health assessment of 11 districts in Madhya Pradesh, India has revealed that in most of the districts only few fields with adequate levels of sulphur, boron, zinc and phosphorus indicating their widespread low levels. Potassium was in general adequate. Farmers’ current blanket fertilization practices focused at macronutrients viz. nitrogen, phosphorus and potassium only, thus does not meet the variable soil fertility needs. Through participatory action research on soil test based fertilizer application, farmers realized benefits in crop productivity to the tune of 5 to 45% in the season of application and additional yield by 5 to 27% due to residual effects of S, B and Zn in succeeding three seasons. An economic assessment showed the balanced nutrition a profitable option in the 1st season itself. In current rainy fallow regions, the landform management as broadbed and furrow or conservation furrow along with balanced nutrition has shown that fallow lands in black soil regions in Madhya Pradesh can be successfully cultivated to grow soybean crop. In succeeding post-rainy season, the rainy season cultivated plots also yielded more as compared to adjoining plots having one crop only in post-rainy season. This study thus found that soil test based fertilization and landform management are the twin technologies for sustainable crop intensification in black soils of Central Indian region.

Traditional ecological knowledge on shifting cultivation and forest management in East Borneo, Indonesia

ABSTRACTForest utilization of indigenous communities is intimately connected to experiences and knowledge arising from the interaction between people and their environment. The traditional ecological knowledge of the Dayak Tunjung communities in East Borneo offers an interesting example of the interrelation between agricultural food production, forest management and local culture. This study describes how the local villagers manage their rice cultivation system combined with forest succession based on traditional ecological knowledge. Data were obtained through direct participatory techniques by interviewing key informants about their practices and perception as well as field observations on farming activities and forest management. Traditional ecological knowledge on food production and forest management has evolved over many generations but is degrading rapidly. The Dayak people base their practices on a shifting cultivation system of rice intercropped with other foods, while at the same time maintaining forest succession after abandonment. Traditional knowledge relates to ecological reasons for different shifting cultivation stages, selection of suitable cultivation plots, soil classification and culturally embedded ‘signs of nature’ – which signs to look out for during which month of the year and which activities to undertake. Throughout Indonesia, traditional ecological knowledge can prove to be instrumental for future forest resource and conservation management.EDITED BY Leni Camacho

Macropropagation and Production of Clonal Planting Materials of &lt;i&gt;Panax pseudoginseng&lt;/i&gt; Wall.

Panax pseudoginseng Wall., a highly medicinal, herbaceous, long-lived plant, grows in the forest litter of shady primary forest. The species is threatened in the natural habitat due to unsustainable harvesting of rhizome for medicine and habitat destruction. The species has very poor adaptive power to the synthetic environment and fails to grow and propagate. Present study was undertaken to develop suitable low cost propagation technique and produce clonal planting materials through rhizome splitting and root cutting. Rhizomes and roots were cut into segments and sowed in the raised soil bed prepared by mixing decayed wood powder, sand and top black soil at 1:1:3 ratios in a shaded poly house. Of the sowed rhizome segments ~55% segments remained recalcitrant to morphogenetic response in the first year of the study and the response improved in the subsequent years. In the third year ~51% rhizome segments responded positively. The horizontal root cuts mostly remained morphogenetically dormant but inclined root cuts exhibited better response. The morphogenetic response from the roots was comparatively very poor compare to rhizome segments. The plantlets formed both rhizome segments and root cuttings were maintained for three years in the bed/pots followed by transferring in the cultivated plots.

A comparison of nutrient losses to waters following pasture renewal by cultivation or direct-drilling

Agricultural soils enriched in phosphorus (P) have been linked to increases in P losses and declining water quality. Cultivation of pastures near sensitive waterways lowers surface soil P and therefore the concentration of P in surface runoff. However, such a practise can increase the mineralisation of organic nitrogen (N), negating this as a mitigation option for N sensitive catchments. A field trial was set up to compare pasture renewal using either direct-drilling or cultivation (which mixed the plough layer to 150 mm) on hydraulically-isolated runoff plots at Tussock Creek near Invercargill, Southland. The trial ran from March to December 2015. Soil P concentrations (0-150 mm depth) decreased in the cultivated plots by about 20%, 8 months after cultivation. Concentrations of nitrate-N in surface runoff and shallow drainage, and P in shallow drainage only, were not different between directdrilling and cultivation treatments. Cultivation reduced filterable reactive P (FRP) losses in surface runoff by 69% (P=0.047) compared to direct-drilled plots. This study showed that mixing P within the plough layer decreased P loss over the 10 months of measurement. Conventional tillage that inverts the plough layer may result in even larger decreases in soil P concentrations. Tillage can therefore be used as a strategy to decrease P loss in small areas where surface runoff is likely, with little risk of increasing catchment-scale N loss. This includes near stream areas, but care must be taken to leave an adequate buffer strip to prevent sediment (and P) loss via erosion of bare soil. Keywords: phosphorus-enriched soil, cultivation, direct-drilling, runoff, drainage

Soil microbial biomass dynamics in grassland and agroecosystem receiving varying resource quality soil inputs in dry tropics

Atwo year field experiments were conducted to evaluate the effect of land use conversion and management strategies variation through addition of varying resource quality soil inputs on soil microbial biomass dynamics, under rice-wheat-summer fallow crop sequence in tropical dryland agroecosystem. The treatments involved addition of equivalent amount of N through chemical fertilizer (CF) and three organic inputs, viz. Sesbania shoot (high quality resource, HQR), wheat straw (low quality resource, LQR) and Sesbania+wheat straw (mixed quality, MQR) besides control (CO) and grassland (GF). On annual mean basis, cultivation of grassland decreased the MBC (−51%) and MBN (−52%) level in soil. Relative to control, application of WS+SS considerably increased the level of MBC (+77%) and MBN (+87%) in soil, instead of SS, WS and CF. In all cultivated plots, a distinct seasonal and temporal variation in microbial biomass C and N were found contrary to GF. Both soil MBC and MBN level increased from rice to wheat period and reached maximum during summer fallow; during rice, the pattern in decreasing order was HQR>MQR>LQR>CF>CO; wheat period, MQR>LQR>HQR>CF>CO; summer fallow, MQR>LQR>HQR>CF>CO. It is concluded that cultivation exerts negative effects on the concentration of soil microbial biomass. Application of varying resource quality exogenous soil inputs maintains the microbial biomass level in soil, differentially. Addition of MOR was most effective for sustained buildup of microbial biomass in soil throughout the cycle, rather than HQR, LQR or CF. The fertility of soil in term of soil microbial biomass can be maintained by regulating the resource quality of exogenous inputs, and these results will help in designing the management strategies for sustaining long term soil fertility in these tropical dryland agroecosystem.