Quantcast


CURATOR
A pinboard by
Khalid Hussain

Post Doc/AP, University of Agriculture, Faisalabad-Pakistan

PINBOARD SUMMARY

Save the mountains from soil loss for sustainable crop production through soil conservation measures

Humans obtain about 99.7% of their food calories from land and around 0.3% from aquatic ecosystems, worldwide, so crop land conservation and maintaining soil fertility for food production should be given highest importance as human welfare. World’s two billion hectares of agricultural land is already affected by soil degradation and each year around 10 million hectares of world’s crop land are being lost due to soil erosion which directly reduces world food production. Farmers’ choice of cultivation depends on two main points; the first focus is to cultivate a crop to secure food for his household and the second focus is market demand of a specific crop. The cultivation is often done on just deforested uplands with various degrees of slope which encourages soil erosion. Therefore, soil degradation is a common problem of uplands, mostly due to inappropriate cultivation practices while slope length, rainfall erosivity, steepness, soil erodibility, conservation practices and crop management are considered as main factors influence soil erosion. So save the land to save the humanity is the slogan of my research area. I am working on soil conservation practices including agroforestry, mulching, green manuring, soil cover maintenance etc to save the most fertile upper soil layer in hilly areas. Agroforestry is an approach of land use with inclusion of trees into farming systems which allows production of trees and crops or livestock from same piece of land to get ecological, cultural, economic and environmental benefits. I think continuous experimentation, modification and even more important farmers’ education are key factors for developing and further improving these conservation systems. Moreover, my researche is focused on enhancing the productivity of uplands or hillside agriculture and make the poor hillside farmers food secure.

5 ITEMS PINNED

Nitrogen use efficiency of monoculture and hedgerow intercropping in the humid tropics

Abstract: The design of productive and efficient intercropping systems depends on achieving complementarity between component species’ resource capture niches. Spatiotemporal patterns of capture and use of pruning and urea nitrogen (N) by trees and intercrops were elucidated by isotopic tracing, and consequences for nitrogen use efficiency were examined. During the first cropping season after applying urea−15N, maize accounted for most of the plant 15N recovery in Peltophorum dasyrrachis (33.5%) and Gliricidia sepium (22.3%) hedgerow intercropping systems. Maize yield was greatest in monoculture, and maize in monoculture also recovered a greater proportion of urea 15N (42%) than intercropped maize. Nitrogen recovery during active crop growth will not be increased by hedgerow intercropping if hedgerows adversely affect crop growth through competition for other resources. However, hedgerows recovered substantial amounts of 15N during both cropping cycles (e.g. a total of 13–22%), showing evidence of spatio-temporal complementarity with crops in the spatial distribution of roots and the temporal distribution of Nuptake. The degree of complementarity was species-specific, showing the importance of selecting appropriate trees for simultaneous agroforestry. After the first cropping season 17–34% of 15N applied was unaccounted for in the plant-soil system. Urea and prunings N were recovered by hedgerows in similar amounts. By the end of the second (groundnut) cropping cycle, total plant 15N recovery was similar in all cropping systems. Less N was taken up by the maize crop from applications of labelled prunings (5–7%) than from labelled urea (22–34%), but the second crop recovered similar amounts from these two sources, implying that prunings N is more persistent than urea N. More 15N was recovered by the downslope hedgerow than the upslope hedgerow, demonstrating the interception of laterally flowing N by hedgerows.

Pub.: 01 Jan '05, Pinned: 09 Sep '17

Leucaena hedgerow intercropping and cattle manure application in the Ethiopian highlands II. Maize yields and nutrient uptake

Abstract:  The effects of Leucaena leucocephala and L. pallida prunings and cattle manure on maize nutrient uptake and yield were investigated in a hedgerow intercropping trial in the Ethiopian highlands. Hedgerow intercropping (also called alley cropping) is an agroforestry system in which trees are grown in dense hedges between alleys where short-cycle crops are grown. The hedges are pruned periodically during the cropping period and the prunings are added to the soil as green manure. For each leucaena species, the experiment had 16 treatments resulting from a factorial combination of four levels of leucaena leaf prunings (no prunings applied; first prunings applied; first and second prunings applied; first, second and third prunings applied), two levels of air-dried cattle manure (0 and 3 t dry matter ha–1) and two levels of N fertilizer (0 and 40 kg N ha–1 as urea). Uptake of N, P and K increased significantly with application of the three nutrient sources, but uptake of Ca and Mg either did not respond or decreased with application of prunings and manure. All the three factors increased maize grain and stover yields significantly, usually with no significant interactions between the factors. At least two applications of prunings were required to significantly increase nutrient uptake and maize yield. Maize in the row closest to the hedge did not respond to these nutrient inputs. It is concluded that hedgerow intercropping, with or without manure application, can increase crop yields moderately (to 2–3 t ha–1 maize grain yields) in the highlands, but P, Ca and Mg may have to be supplied from external sources if they are deficient in the soil. Additional N is still required for higher yields (>4 t ha–1 maize grain yields). However, quantification of the competition effects of the trees is also required to confirm these results.

Pub.: 01 Jan '99, Pinned: 09 Sep '17

Combining δ13C measurements and ERT imaging: improving our understanding of competition at the crop-soil-hedge interface

Abstract: Hedgerow cropping decreases erosion in hillside agriculture but also competes for water and nutrients with crops. This study combined two methods for an improved understanding of water and nutrient competition at the crop-soil-hedge interface.δ13C isotopic discrimination in plants and soil electrical resistivity tomography (ERT) imaging were used in a field trial with maize monocropping (MM) vs. leucaena hedgerow intercropping with and without fertilizer (MHF+ and MHF−) in Thailand.Hedges significantly reduced maize grain yield and aboveground biomass in rows close to hedgerows. ERT revealed water depletion was stronger in MM than in MHF+ and MHF- confirming time domain reflectometry and leaf area data. In MHF+, water depletion was higher in maize rows close to the hedge compared to rows distant to hedges and maize grain δ13C was significantly less negative in rows close to hedges (-10.33‰) compared to distant ones (-10.64‰). Lack of N increased grain δ13C in MHF- (-9.32‰, p ≤ 0.001). Both methods were correlated with each other (r = 0.66, p ≤ 0.001). Combining ERT with grain δ13C and %N allowed identifying that maize growth close to hedges was limited by N and not by water supply.Combining ERT imaging and 13C isotopic discrimination approaches improved the understanding of spatial-temporal patterns of competition at the hedge-soil-crop interface and allowed distinguishing between water and N competition in maize based hedgerow systems.

Pub.: 15 Apr '15, Pinned: 09 Sep '17

Effects of terracing and agroforestry on soil and water loss in hilly areas of the Sichuan Basin, China

Abstract: Soil erosion in hilly areas of the Sichuan Basin is a serious concern over sustainable crop production and sound ecosystem. A 3-year experiment was conducted using the method of runoff plots to examine the effects of terracing and agroforestry in farmland systems on soil and water conservation of slope fields in the hilly areas in Jianyang County, Sichuan Province, Southwestern China. A power function (Y = aXb) can statistically describe the relationship between water runoff (Y) and rainfall (X). The regression equation for the treatment of sloping terraces with crops (Plot 2) is remarkably different from that for the treatment of sloping terraces with grasses and trees (Plot 1) and the conventional up-and down-slope crop system (Plot 3) regarding equation coefficients, while regression equations are similar between Plot 1 and Plot 3. Water runoff amount and runoff coefficient of slope fields increased by 21.5∼41.0 % and 27.5 ∼ 69.7 % respectively, compared to those of sloping terraces, suggesting that terracing notably reduced the water runoff in the field. In the case of sloping terraces, lower amount of water runoff was observed on sloping terraces with crops than on sloping terraces with grasses and trees. Sediment yields on the slope fields in the normal year of rainfall distribution were notably higher (34.41 ∼ 331.67 % and 37.06 ∼ 403.44 % for Plot 1 and Plot 2, respectively) than those on sloping terraces, implying that terracing also plays a significant role in the reduction in soil erosion. It is suggested that terracing with crops is significantly effective for soil and water conservation in cultivated farmland, while the conventional practice of up-and down-slope cultivation creates high rates of water runoff and soil sediment transport. Terracing with grasses and fruit trees shows a less reduction in water runoff than terracing with crops, which was observed in the 3-year experiments.

Pub.: 28 Aug '08, Pinned: 09 Sep '17

Modelling resource competition and its mitigation at the crop-soil-hedge interface using WaNuLCAS

Abstract: Abstract Agroforestry systems have a large potential to increase systems’ productivity and provide soil conservation in hilly terrain but comprise complex interactions at the crop-soil-tree interface. Modelling can be an operational approach to unravel the later. We used the spatially explicit, dynamic Water Nutrient and Light Capture in Agroforestry Systems model to (i) predict maize above ground biomass (AGB) and interactions at the crop-soil-hedge interface, (ii) improve our understanding of trees’ impact on crops in alley cropping, and (iii) identify mitigation strategies. A 2-year-data set from a soil conservation experiment in Western Thailand with maize farmers’ practice (monocropping, tillage), maize-chili-hedgerow intercropping (±fertilization; minimum tillage) was used as model input. Model validation showed satisfactory results for maize AGB (R2 = 0.76, root mean square error = 4.2, model efficiency = 0.69). Simulations revealed nitrogen (N) and phosphorus (P), rather than light and water, as main limiting factors at the crop-soil-hedge interface reducing maize AGB in rows close to hedgerows. Growth limitation by P was stronger than that of N while light competition was alleviated by four to six hedgerow prunings already. WaNuLCAS simulations clearly indicated that small-targeted additional N and P dressings to maize in rows close to hedges helped overcoming nutrient competition. Such strategic management options can be done for local farmers’ and hence, foster adaptation of soil conservation techniques for sustainable crop production in future.AbstractAgroforestry systems have a large potential to increase systems’ productivity and provide soil conservation in hilly terrain but comprise complex interactions at the crop-soil-tree interface. Modelling can be an operational approach to unravel the later. We used the spatially explicit, dynamic Water Nutrient and Light Capture in Agroforestry Systems model to (i) predict maize above ground biomass (AGB) and interactions at the crop-soil-hedge interface, (ii) improve our understanding of trees’ impact on crops in alley cropping, and (iii) identify mitigation strategies. A 2-year-data set from a soil conservation experiment in Western Thailand with maize farmers’ practice (monocropping, tillage), maize-chili-hedgerow intercropping (±fertilization; minimum tillage) was used as model input. Model validation showed satisfactory results for maize AGB (R2 = 0.76, root mean square error = 4.2, model efficiency = 0.69). Simulations revealed nitrogen (N) and phosphorus (P), rather than light and water, as main limiting factors at the crop-soil-hedge interface reducing maize AGB in rows close to hedgerows. Growth limitation by P was stronger than that of N while light competition was alleviated by four to six hedgerow prunings already. WaNuLCAS simulations clearly indicated that small-targeted additional N and P dressings to maize in rows close to hedges helped overcoming nutrient competition. Such strategic management options can be done for local farmers’ and hence, foster adaptation of soil conservation techniques for sustainable crop production in future.2

Pub.: 01 Dec '16, Pinned: 09 Sep '17