 Well, let me thank our two discussants and open up the floor for more questions that can come in. Meanwhile, I'll think some more about the answer to your question, Mahmood. Yes, Jim? Are there any long-term consequences for other nutrients when you start removing two and three times the grain that you were before? In other words, you know, phosphorus, potassium, are there replacement issues there? Let me take a number of questions. We'll just kind of integrate those and then discuss them so I can respond to them. Yes? I mean, you know, who did the trials for the trees in the mill field? Over what period of time are they quantified to that? In the back? Yeah. The maize yields raised quite dramatically, but the other yields didn't. They went down, and so I had, what about rotations? What does that mean for that? Good point. Yes. If all the crop stover is used for either animal production or biofuel production in Iowa, what does that do to the soil structure in the field? Well, let's listen. You didn't have a question. That's very... You're waiting for the powerful one, I'm sure. Well, let me address a few of the questions you referred to, Keisha's, and then ask my colleagues to for me. The issue of maize yields versus yields of other crops. Yes, indeed, the real positive effects, sustained positive effects that we're talking about are very well noted for maize, millet, sorghum, and other cereal crops. For the lake, humanist crops like soybeans and cow peas, generally the response is just about zero. It's neutral, which may be expected because they are nitrogen-fixing themselves. So statistically, there are ups and downs, but basically the long-term yields show about a zero response. With cotton, it's zero to a slight reduction, and that's due to greater vegetative growth in the plants, less mold from forming under the canopy of the trees. So that's the general response. And I think a couple of people have asked about the issue of crop rotations and their importance in Zambia, so I'll ask Colard to address that one. On the question of soil fertility, indeed, the soil fertility in association with the canopy of the trees in these systems is generally much improved. Double or triple the nutrient contents of NPK, calcium, magnesium, micronutrients is generally seen in those conditions. However, and I think it's an important point that you're probably alluding to, Jim, is that we're not looking at this as a replacement for the use of fertilizer. This is basically a means of jacking up the potential of the system and making it more attractive to use the appropriate rates of fertilizer like nitrogen, phosphorus, and lime so that one can sustain those yields over long periods of time. So although you're producing tons of nutrient-rich biomass, you're not going to be keeping that system going indefinitely without the use of other supplemental fertilizer, particularly top-dressing nitrogen and phosphorus for bee-efficient soils. So it's not an organic agriculture system, per se. It's a means of attracting farmers. And I mentioned 80% of farmers in Africa use no fertilizer. So getting them engaged in the use of fertilizer means increasing fertilizer efficiency, which is what the system does. You were asking about the nature of how long the... In over a long period of time. Yes, and the research on this particular species started in 1952 and Oxford Forestry Institute published a monograph a few years ago with 700 published references on this topic. So it is quite surprising how little is known about this. I suppose perhaps the majority of people in this room have never heard of these systems. But it is the case that the science is there, but the actual bridge or crossing the bridge to large-scale upscaling has been a problem. The competition between biofuels, livestock and soil conservation. I think you should answer that one, Carlos. Answer not, but just acknowledge that it's a serious trade-off. And I think that's one of the reasons, for example, why conservation agriculture frequently is not adopted by small holders when they have animals. And I think the whole research and how much of that biome has to be left on the ground versus fed through the room. And obviously how you handle manure and bring that back. I think it's still a big empirical question, but we'll have to deal with that more and more. Particularly if so, second-generation biofuels really takes off. I agree. Let's do it up around. Since this is known, you say since 1952, why did it take off? I often ask that question. I think there are two fundamental issues. What is the mindset of Western agriculture? I mean, this is so dramatically alien to Western agriculture. And of course these systems cannot be used in the United States, for example, because your growing season is too short. You don't have a year-round growing season where you can't actually have the principle of reverse phenology successful. So, agriculturists in Africa, for example, have been trained in western science. That's all the bachelor's and PhD programs are all western oriented. And these systems were actively discouraged for the last 50 years. I mean, not just neutral, they've been discouraged. Farmers have been told to clear their fields. Projects have been based on the imperative of clearing fields of trees to grow crops. And although the African farmer recognized these systems and nurtured these trees over the generations, it has not been achieved. It has not crossed the line into recognition via western agriculture. That's number one. Number two is propagation systems. What you saw in most of these pictures were natural regenerated populations of these trees. The tree seed was present in the fields due to livestock spreading through the agricultural landscape. And when it came out, farmers nurtured the trees, protected them, and produced these agroforests. But in large parts of Africa, you don't have the trees, and therefore there are no trees in the system. And propagation has always been a problem because there's a unique constraint set of constraints to producing seedlings and planting them out in the field. That has been linked now over the last 10, 15 years by a whole series of research. And now we can confidently, as they're doing in Zambia, propagate with hundreds of thousands of farmers at the simple growing of the seeds and establishing them in the crop. Next question. Yes. I have a question. I have a comment. I work at the Pacific Islands, and agroforestry systems have been in use for close to 3,000 years as an integrated system that incorporate the livestock. And I think they can be an extra model for other parts of the world, particularly these French-based agroforestry systems. I think that we don't need to reinvent the wheel. I think we need to look at parts of the world where the systems work and are still functioning. That's under higher rainfall area, significantly higher rainfall than what we've seen here. Absolutely true. And some of you may know the famous book by Russell Smith, a professor at Pennsylvania State University who wrote a book in 1929 about perennial tree crops, the future of American agriculture. Well, it never went that way so far, but maybe in the next century we'll be seeing a revisit of that vision. Yes. Other questions? I hope that's a better question. Okay. Let's have this gentleman here. You mentioned the presentation on Zambia, the 25 to 40 percent of the maize planted by small movers was abandoned. Can you elaborate on why that was and what the factors that were looking at? Great. Also on Zambia, the question on cover crops, how important they were, and also if I understand from FAO colleagues, especially on the mechanization front, that a key factor was an improvement of implements to, let's say, facilitate conservation agriculture that took time to develop. But I'd like to get your take on that also. Okay. Yeah, thank you very much. Maybe I start with the why 40 percent of our planted areas abandoned. The most driver for that has been the weed infestation. In the quest to try and produce more, when the production efficiencies and your capacity is limited, so we've got people trying to plant more than two to three hectares and they are overwhelmed by weeds because they have just a short window to plant weed and everything and then you realize by half the way down the line they can only do maybe one and a half hectares and then they don't have fertilizer also to boost the rest of the crop. So mostly it's because they waited for the rains to come and want to do all operations within a short window and they got overwhelmed with weeds. This is why I think the uptake of appropriate use of herbicides has just shot. Last year we recorded up to about 500 percent increase to a point where we read a shot of herbicides and this summer has now attracted a lot of private companies and also has gone dealership for netweeds. Coming around wherever we are promoting conservation farming to see how they can promote judicious use of herbicides. The other reason was purely the livestock crop interaction which with communal grazing they couldn't handle if you don't have fencing and the like, so there was that conflict. The cover crops, yes. Now, like I said, in Zambia we're trying to promote food legends. We did other policies but due to the poor marketing they are not picking up. So what we've done is to bring in food legends, cowpeas, groundnuts and that we have seen it is very popular because one, it is helping to cover the hunger period. We have a unique scenario among small hoarders in Zambia where during their peak level periods that's when they have low food stocks. So cowpea for instance comes in handy within the first month of the red season by the end of January and February they are able to reap from there so it has become very popular and they can do quite a lot of it and that is what actually waits well as the cover crop. We have seen in some areas like for instance I think I saw a Manawan colleague here and in Zambia trying to shift some cover crop or some dry stovar to take to the farm. Probably that could wait for a hectare but if you're talking about a slightly bigger area like our oxen farmers that the economics I think couldn't wait. So the uptake and also the uptake of crop rotations really has been driven much as the utility of the type of cover crops you are making and also how the market is developing around those cover crops. So that's what we are trying to do and I also wanted to attempt quickly why the slow takeoff. I think you are talking of poverty stricken small scale farmers whose immediate need is to put food on table. Now talking of someone to plant a tree whose benefit will start showing in 10 years to come sometimes may seem very obscure but what we've seen is over time people have started seeing the benefit instead of actually shifting to try and open new marginal lands they've seen the benefit of doing all these things simultaneously so that they are able to start getting a bit of food down and over time they are building on the soil fertility and there is a bit of permanency in their fields.