Oil palm is the most rapidly expanding tropical perennial crop. Its cultivation raises environmental concerns, notably related to the use of nitrogen (N) fertilisers and the associated pollution and greenhouse gas emissions. While numerous and diverse models exist to estimate N losses from agriculture, very few are currently available for tropical perennial crops. Moreover, there is a lack of critical analysis of their performance in the specific context of tropical perennial cropping systems. We assessed the capacity of 11 models and 29 sub-models to estimate N losses in a typical oil palm plantation over a 25-year growth cycle, through leaching and runoff, and emissions of NH3, N2, N2O, and NOx. Estimates of total N losses were very variable, ranging from 21 to 139 kg N ha-1 yr-1. On average, 31 % of the losses occurred during the first 3 years of the cycle. Nitrate leaching accounted for about 80 % of the losses. A comprehensive Morris sensitivity analysis showed the most influential variables to be soil clay content, rooting depth, and oil palm N uptake. We also compared model estimates with published field measurements. Many challenges remain in modelling processes related to the peculiarities of perennial tropical crop systems such as oil palm more accurately. © Author(s) 2016.
Tag: cropping systems
Soil fertility management in semi arid areas of east and southern Africa
The Arid and Semiarid areas in Sub-Saharan Africa occur mainly around the latitude 10 -15 N IN west Africa and roughly 10 -30S in Southern Africa.In addition there is also a large arid and semi-arid region in The Horn of Africa and East Africa.Another largo dry region exist in South-Western and South-Estern Africa, consisting of semi-arid strip that runs roughly North and South inland in Namib Desert, eastwards in a broad belt through Botswana, and then south through the center of South Africa.Smaller semi-arid areas are also found in Zimbabwe,Mozambique and Madagascar.
Agroforestry systems: some definitions and contribution to forests dynamics
Agroforestry is probably one of the most controversial word for the definition of a combination, or intergration of trees (foresty components) and crops or fodder (agricultural components) into various types of cropping systems. Agroforestry systems varies from the most simple (SAF), a crop associated with a tree, to the most complex in terms of structure, the CAF (Complex agroforestry system) with multistrata components, a large biodiversity in terms of species and frequencies, where several perennial crops and trees are associated. After describing rapidly the concept of agroforestry, we will focus on a particular typology and provide two examples of simple agrofest (SAF), parkland in Africa, and complex agroforest (CAF) in Indonesia.
Adaptation of Crops to Partial Shade in Mixed Cropping Systems
This chapter focuses on the adaptation of crops to their habitat, and specifically to shade. It also examines adaptation parameters (leaf morphology and anatomy, chloroplast structure and characteristics, chlorophyll content and fluorescence, and net photosynthesis and stomatal conductance) that can be used as criteria for the selection of shade-tolerant plants. The direct and indirect effect of shade trees on crops are also discussed.
The development of pepper (Piper nigrum L.) foot rot disease on agroforestry
Pepper foot rot is one of the most destructive diseases. There were three cropping patterns in the research area, i.e., agroforestry, pepper-cocoa and pepper monoculture patterns. As one of the most common cropping patterns, the observation of foot rots in the agroforestry pattern compared to other cropping patterns. The study was conducted in Simbune Village, East Kolaka Regency, Southeast Sulawesi, from October 2013 to September 2014. The research was conducted by direct observation methods. In each cropping pattern, a permanent measurement plot was made by sampling 30% of the total pepper individuals. The intensity of the disease was observed monthly for 12 months. The observation revealed that the intensity of foot rot disease was getting more severe toward the end of observation. The intensity on agroforestry (26% – 33%) and pepper-cocoa (17% – 35%) patterns were lower than that on pepper monoculture pattern (85% – 90%). The infection rate was lowest on the agroforestry pattern with a value of 0.051. This finding suggested that the agroforestry pattern for pepper showed the best resilience against foot rot disease. © Published under licence by IOP Publishing Ltd.